Pharm Unit 2 - Shelbye's CSON Notes Blog



Pharm Unit 2

Special concepts r/t Antimicrobials

• Selective toxicity

– Ability to target without harming host

• Susceptibility

• Prophylaxis

– Neutropenia, Surgery, Endocarditis

• Combination Therapy

• Misuse – non-specific fevers, viruses

Resistance

Ch. 86

Aminoglycosides: Background

• Resistance is beginning to limit use

– Gentamicin – cheaper but commonly used

– 20 diff aminoglycoside-inactivating enzymes

– Reserve amikacin

• Bactericidal

– concentration dependent

– Post-antibiotic effect – several hours (prolonged)

– NOT effective against anaerobes

|Gentamicin (Garamycin) |

|MOA/ Use |Narrow spectrum for gram negative bacilli- especially pseudo. Aerugenosa, E. coli, Klebs, Serratia |

|ADME |Poor CSF |

| |Not absorbed orally |

| |Toxicity with wound irrigation |

| |Binds tightly to renal tissue |

| |Excretion primarily renal |

| |Dosage varies widely (.5 mg/kg to 25 mg/kg) |

|Adverse Effects |Ototoxic |

| |R/t excess trough levels- sensory hairs |

| |HA, N, vertigo then high- pitched tinnitus (action?) |

| |Vestibules of ears and absorbs into tissues to kidney |

| |Nephrotoxic |

| |Total cumulative dose |

| |ATN (acute tubular necrosis- leads to renal failure) -- proteinuria, casts (slough or big particles), increased BUN,|

| |increased Creatinine |

| |Elderly and children at risk |

| |Neuromuscular blockade |

| |Flaccid, weak muscles |

| |Dosage based |

| |Neurotoxic with peripheral muscles |

| |Hypersenditivity & blood dyscrasias (rare) |

|D = D |PCNs, Cephs, Vanco used in combo |

| |PCNs inactivate – schedule issue? |

| |Ethacrynic Acid – ototoxicity |

| |Other nephrotoxics |

| |Skeletal Muscle relaxants |

Aminoglycosides: Special concerns

• Neomycin most nephrotoxic

• Scheduling once daily – Safer?

– Post-antibiotic effect

– Washout – esp. in vestibule and kidneys

– Typically only measure trough – up to 1hr prior to next dose – level should be ?

Ch. 91 Antifungal Agents

Systemic mycotic infections

• Opportunistic (host is immunocompromised, malnourished, ill): candidiasis, aspergillosis, cryptococcosis, mucormycosis

• Nonopportunistic: sporotrichosis, blastomycosis, histoplasmosis, coccidioidomycosis

Superficial mycotic infections

• Candidiasis

• Dermatophytes

Major Classes of Antifungals

• Polyenes

• Azoles

• Pyrimidine analogs

• Echinocandins

|Amphotericin B (Fungizone) |

|MOA/ TE |Broad spectrum antifungal agent binds to ergosterol component of fungal cell wall and increases permeability. |

| |DOC for most progressive, potentially fatal systemic mycoses |

|ADME |Highly toxic (sterols) |

| |Poor GI absorption - SLOW IV USE ONLY |

| |Poor CSF |

| |Break down human sterols and bug sterols |

|Adverse effects – almost 100% - varying |Phlebitis |

| |Fever, chills, nausea – pre-treat w benadryl / acetaminophen |

| |Nephrotoxicity – residual if (4 g/day, 1 L NS, Monitor q 3-4 days |

| |Hypokalemia |

| |Bone marrow suppression |

|D(D |nephrotoxics - flucytosine |

|Itraconazole (Sporanox) |

|MOA/ TE |Azole group of antifungal agents that inhibits sythesis of ergosterol – fungistatic to treat histoplamosis, meningitis |

| |of cryptococcus neoformans & disseminated candidiasis |

|ADME |PO or IV |

| |Food ( abs. capsules, ( abs. of suspension |

| |Metabolized in liver |

| |40% excreted unchanged in urine |

|Adverse Effects |Common – N, V, and D, rash, HA, edema |

| |Rare - Hepatic necrosis, transient cardiosuppression |

|D(D |Inhibits cytochrome P450 isozymes |

| |Increases levels of warfarin, digoxin, sulfonylureas, cyclosporine, quinidine and many other drugs |

| |Acid reduces decrease drug levels |

| | |

| |**if system is impaired, drug levels will rise (cytochrome P450 isozymes) |

Azoles: Special Considerations

• Fluconazole [Diflucan]

– Lower toxicity level

– Can be taken orally

– SJS syndrome (Stephen Johnson syndrome)

• Ketoconazole [Nizoral]

– Effect on sex hormones – inhibits production

Drugs for Superficial Mycoses

• Dermatophytic infections (e.g., ringworm)

– Tinea pedis, tinea corporis, t. cruris, & t. capitis

• Drugs

– Clotrimazole (Gyne-Lotrimin) – DOC for topical dermatophytic and candida infections of skin, mouth, vagina

• Vulvovaginal candidiasis

– Griseofulvin (Grifulvin) - oral

• onychomycosis

|Griseofulvin (Grifulvin V) |

|MOA/ TE |Superficial mycoses only – inhibits fungal mitosis – incorporates into keratin |

|Adverse Effects |Transient headache, rash, GI |

| |Contraindicated in hepatocellular disease |

|D(D |Decreases warfarin |

Ch. 92 Drugs fro Non-HIV Viral Infections

Viral Infections

• Dilemma

• Types

– HSV (Herpes-simplex)

• Genitalia, mouth, face (HSV-2)

• More sensitive to antivirals, less resistant

– VZV (Varicella Zoster)

• Chicken pox – Shingles

• Moderate sensitive

– CMV (Cytomegalovirus)

• Less sensitive and more resistant

|Acyclovir (Zovirax) |

|MOA/ TE |Suppress synthesis of viral DNA and is useful in treating HSV1,2 & VZV – no cure |

|Adverse Effects |Intravenous: reversible nephrotoxicity, phlebitis |

| |Infuse slowly – hydration – during & 2 hr after |

| |Oral: GI, vertigo |

| |Topical: stinging |

|Nursing Implications |Resistance – type of clients |

| |IV indicated for oral lesions in |

| |STI control |

| |Treatment for VZV in elderly and children (w/in 24 hr) |

| |ONLY give po (low availability), topically or IV |

| |NO IV bolus, NO IM, or NO SubQ injections |

| |Valacyclovir [Valtrex] – prodrug that increases oral bioavailability by 55% |

| |Without regard to meals |

| |*check to see if admin is correct in book |

| |Bolus- def. |

|Ganciclovir (Cytovene, Vitrasert) |

|MOA/ TE |Suppresses replication of viral DNA to treat CMV retinitis of immune compromised clients & prevent CMV in transplant |

| |patients |

|Adverse Effects |Granulocytopenia & thrombocytopenia |

| |Mutagenesis, carcinogenesis |

| |Teratogenisis and infertility – (90d following cessation) |

| | |

|Valganciclovir (Valcyte) – prodrug for oral |Take intact – with food |

|use | |

Hepatitis C (HCV)

• Transmission—blood and semen

• Typically asymptomatic

• Leading cause for liver transplants

• Among most common causes of liver cancer

• Not curable, only suppressible

• Drugs

– Pegylated interferon alfa combined with ribavirin

|Interferon alfa (Peg-Intron) |

|Immune modulatory, antineoplastic, antiviral |

|MOA/ TE |Blocks entry of virus, synthesis of viral m-RNA and proteins, and viral assembly. Tx of chronic Hep B & C |

|ADME |Pegylated - makes drug longer acting |

| |Only parenterally (SubQ) |

|Adverse Effects |Flu-like (fever, myalgia, HA, fatigue) & depression |

| |Long/High dose – thyroid dysfunction, heart damage, bone marrow suppression |

| |Alopecia, GI, injection site pain, bruising |

|Ribavirin (Rebetol) |

|MOA unclear |Used with Interferon A - together are DOC for Hep C (HCV). |

| |Therapy 24 to 48 weeks. Goal is SVR – sustained virologic response (loss of detectable viral |

| |RNA) |

|Adverse Effects |Hemolytic anemia (a lot of RBCs that are broken) |

| |Teratogenic (Category X) – two forms of BC |

|Dosage |Based on weight |

|Teratogenic |Can kill fetus |

Hepatitis B - HBV

• Transmission—blood and semen

• Drugs

– HBV vaccine

– Interferon alfa-2b [PEG-Intron]

– Lamivudine [Epivir-HBV]- already developing resistance

– Adefovir [Hepsera]

• Duration of treatment and relapse

Flu Vaccines

• 3 strains – selected by CDC, FDA, & WHO

• Inactivated

– IM

• Live attenuated – LAIV (Flumist) – 2003

– Intranasally

– MUST BE FROZEN

– Only ages 5-49

• Efficacy – Who should receive it?

– 1-2 wks before exposure & lasts for 6 mo

• Adverse effects

– Fever, malaise, myalgia

– Guillain-Barré syndrome – Swine flu vac. 1976

– LAIV – runny nose, HA, cough – rare GBS, anaphylaxis

• Precautions and contraindications

– Acute febrile illness, hypersensitivity to eggs

• Who should NOT without MD approval?

– Allergy to egg

– Previous severe reaction

– GBS

– Moderate, severe illness w/ fever

– Children under 6 months

– LAIV not for: adults over 50, children under 5, pregnants, children or adolescents on long-term ASA therapy, chronic heart, lung disease

Drugs for Influenza

|Oseltamivir (Tamiflu) |

|MOA/ TE |inhibit viral replication of Inf A&B and is used to prevent and treat same – effective if implemented within 2 |

| |days of sxms |

|Adverse Effects |N&V |

| |Confusion, self injury |

|Expensive |Must be started prior to 48 hr |

ATI p. 220 Ch. 32 Antidepressants

General Points

• Most common psychiatric disorder

• Major treatment method - medications

– Five major groups

• Goal?

• Sxms

– Depressed mood, loss of pleasure / interest in all or nearly all of one’s usual activities

• Under-treated

• More prevalent in women

• Suicidal thoughts may increase w Rx

Tricyclic Antidepressants (TCAs)

|Imipramine (Tofranil) |

|MOA/ TE/ Use |Blocks reuptake of the MAO transmitters NE (norepinephrine) and serotonin. Elevates mood, thereby treating |

| |depression. |

| |Other uses: bipolar disorder, neuropathic pain, insomnia, fibromyalgia, OCD |

|Adverse Effects |Orthostatic hypotension, sedation, anticholinergic effects, diaphoresis, cardiotoxicity, seizures, hypomania, |

| |“yawngasm”- orgasm that occurs when they yawn |

|Glands (Table 14-1) |Salivary glands- decreased secretion |

| |Sweat glands- decreased secretion |

| |Bronchial glands- |

|Precautions/ Interactions |TCAs w MAOI can lead to severe HTN |

| |Potentiates drugs like NE (norepinephrine) |

| |Potentiate CNS depressants |

|Antidote |Activated charcoal after gavage |

|Dosing |Based on clinical response – don’t give more than a week supplys |

| |Dose at bedtime once levels achieved – EXCEPT in elderly (cardiac reasons) |

SSRI Antidepressants

|Fluoxetine (Prozac) |

|MOA/ TE/ Use |Selective serotonin re-uptake inhibitor resulting in elevated serotonin levels – elevating mood and relieving |

| |depression. |

| |Helps in bulimia nervosa |

|Adverse Effects |Impotence, weight gain, Serotonin syndrome, withdrawal syndrome, EPS, bruxism (clenching teeth and jaw), bleeding, |

| |hyponatremia. |

| |Some people have w/draw symptoms with this |

|Interactions |MAOIs, Warfarin, & TCAs |

MAOI Antidepressants

|Phenelzine (Nardil) |

|MOA/ TE/ Use |Enzyme – deactivates NE, serotonin, dopamine, and tyramine (NE stimulator) from foods |

| |NOT 1st CHOICE |

| |Relevant P-kinetics |

| |Tyramine |

|Adverse Effects |CNS stimulation – agitation – hypomania – mania – hypotension – HTN crisis – meperidine (hyperpyrexia) |

| | |

| |Deactivates tyramine which deactivates the transmitter |

Atypical Antidepressants

|Bupropion (Wellbutrin) |

|MOA |Action unclear |

|Effect |Stimulant ergo no wt gain |

| |No sexual dysfunction – may augment |

|Adverse Effects |agitation, HA, dry mouth, constipation, wt loss, insomnia, tachycardia, seizure |

|Note |St. John’s Wort (Box 32-2) |

|Other |Used in smoking cessation |

| |Known to bring on seizures |

| |Can enhance sexual functions |

| |Consider this a vitamin (herbal supplement) |

|(ATI p. 203 or 220??) |May have an impact with BCP |

Ch. 34 Classification: Sedative- Hypnotics

Overview

• Venacular

– Anti-anxiety, anti-anxiolytics, tranquilizers

– Hypnotics

• Major Categories

– Benzodiazepines, Barbiturates, Barbiturate–Like

– Miscellaneous

• Major Effects

– CNS depression

• Therapeutic Uses

– Relieve anxiety, facilitate sleep, manage muscle spasms, seizure and panic disorders, augment anesthesia, and manage ETOH withdrawal

Benzodiazepines (CIV) Category D

|Diazepan (Valium) – self limiting |

|Others: clonazepam, lorazepam, clorazepate |

|MOA |Depress neuronal function at multiple CNS sites by potentiating endogenous GABA (gamma-aminobutyric acid) and is |

| |limited because GABA is finite(safer |

|Cardiac |PO effect - heart & blood vessels (not a huge effect) |

| |IV effect – potentially ? (huge effect) |

|Respiratory |Minimal alone, serious if combo or IV |

|Pharmacokinetics |Readily absorbed |

| |Differ in respect to time - course of action |

| |(main indicator for which one chosen for which job) |

|Adverse Effects |CNS – daytime vs. nighttime impacts |

| |Amnesia |

| |Paradoxical- opposite effect |

| |Abuse |

| |Malnutrition, liver disease and blood levels |

|D(D |w/ other CNS depressants |

|Dosage |varies by agent |

|Low Albumin |Low circulation of drug (malnutrition) |

Nursing Implications ATI p. 218

Benzodiazapine-likes

|Zolpidem (Ambien) CIV |

|MOA/ TE/ Use |Agonists at benzodiazepine receptor site on GABA channel prolonging sleep |

| |duration and helps relieve insomnia |

| |Low potential for tolerance or abuse |

|Adverse Effects |Causes sleep walking, or not safe effects for the person |

| |Similar to benzodiazepines (daytime drowsiness / dizziness) |

| |Can intensify CNS depressants |

|Dosage/ Administration |Before bedtime?- about 1 hr before bedtime |

Melatonin Agonist

|Ramelteon (Rozerem) |

|MOA/ TE/ Use |Activates melatonin receptors and rapidly induces sleep to treat insomnia |

|Adverse Effects |Somnolence, dizziness, and fatigue, reduced libido |

|Precautions |ETOH, liver impairment, dangerous activities |

Barbiturates

|Secobarbital (Seconal) |

|MOA/ TE/ Use |Mimics GABA and depresses CNS directly causing relaxation and anxiety reduction. |

| |Other uses: seizure management, anesthesia, sleep disorders, mania |

|ADME |NO CEILING TO LIMITS OF CNS depression (mimics GABA) |

|Adverse Effects |Resp. depression, hypotension in toxic doses, can readily cause death |

|Precautions |Highly addictive - physical dependence – withdrawal can be severe |

| |Caution in elderly |

| |Caution with other CNS agents |

| |Caution with IM injection |

Ch. 37 Drug Abuse

Terms

• Drug abuse- using a drug in a fashion inconsistent with medical or social norms

• Addiction- a disease process characterized by the continued use of a specific psychoactive substance despite physical, psychologic, or social harm

• Cross-tolerance- is a state in which tolerance to one drug confers tolerance to another

• Psychological dependence- an intense subjective need for a particular psychoactive drug

• Physical dependence- a state in which an abstinence syndrome will occur if drug use is discontinued

• Cross-dependence- refers to the ability of one drug to support physical dependence on another drug

• Withdrawal syndrome- a constellation of signs and symptoms that occurs in physically dependent individuals when they discontinue drug use

Table 37-1 Diagnostic Criteria for Substance Abuse and Dependence

Ch. 28 Classifications: Opioid (Narcotic) Analgesics, Opioid Antagonists, Non-opioid Centrally Acting Analgesics

Intro to Opioids

• Chemical class: Opioid vs. opiate

• Functional class: Narcotic Analgesic

• MOA – body peptides (3) enkephalins, endorphins, dynorphins

• Opioid receptors - mu, kappa, and delta

– Agonist, partial agonist, antagonist

• Partial agonist- partially mimics, if give with drug can compete with another drug and negate it or antagonize it--- produces low to moderate activation alone

– Strong and moderate to strong

Table 28-1 Important Responses to Activation of Mu and Kappa Receptors

Opioid Agonists

|STRONG: Morphine (Duramorph) CII |

|MODERATE to STRONG: Codeine (Paveral) CIII |

|MOA/ TE |Mimics action of endogenous opioid receptors (mu) to produce analgesia and thereby relieve pain |

| |Other effects include drowsiness, mental clouding, anxiety reduction, sense of well-being |

|Adverse Effects |Resp. depression |

| |Diminished by “tolerance” |

| |Most common cause of OD death |

| |Others |

| |Constipation, orthostatic hypotension, urinary retention / urgency, cough suppression, biliary colic, emesis (usually |

| |with codeine), elevated ICP (intracranial pressure), dysphoria, sedation, miosis, neurotixicity, immune and hormone |

| |suppression with prolonged use |

| |Toxicity |

| |Classic triad (coma, resp. depression, pinpoint pupils) |

|DON’T USE |Caution: don’t use morphine with head injuries – if there is pressure in the head, the vessels constrict |

|ADME (pharmacokinetics) Nursing Implications|Given by several routes |

| |Slowest to fastest |

| |Time-frame for TE varies by mode of administration |

| |Denatured in liver |

| |Hard to cross blood-brain barrier |

|Precautions/ Contraindictions |Decreased resp reserve, pregnancy, head injury, infants / elderly, hypotension, liver disease |

|Interactions |CNS depressants, antihistamines, antihypertensives, MOAIs*, antiemetics, amphetamines, agonist-antagonist, antagonists |

|Dosage |Highly individualized (Table 28-5) |

|Administration |po, IM, IV, SQ, topical |

| |Oral associated with chronic |

| |Preferably fixed schedule |

| |Site specific – hazards- epidural- effects delayed |

Miosis- pinpoint eyes (constriction)[pic]

Mydriasis- linked to dialated eyes[pic]

Other strong opioids

|Fentanyl (Sublimaze) |Anesthesia primary use (injectable) |

| |100 X mg potency of morphine |

| |Commonly seen as transdermal |

| |No children under 2 / none for under 18 less than 100 lbs. |

|Transmucosal (popsicle) |Breakthrough cancer pain |

| |Store carefully |

| |very large amts of drug |

|Meperidine (Demerol) |Interacts with several drugs |

| |Toxic metabolite |

| |Avoid use past 48 hrs and not to exceed 600mg/24hr. |

|Hydromorphone (Dilaudid) | |

|Methadone | |

|Heroin |Crosses blood-brain easier |

Moderate to Strong Opioid Agonists

|Codeine |Usual dose of 30 mg = about same relief as 325 mg of ASA or Tylenol |

| |Combo meds more effective |

| |Extremely effective cough suppressant at 10 mg dose range |

|Oxycodone (OxyContin) & CR forms | |

|Hydrocodone (Lortab, Norco) CIII | |

|Proproxyphene (Darvon, Darvocet) CIV | |

Special Clinical Concepts r/t Use of Opioids

• Pain assessment – including evaluation!

• Dosing amt and schedule

• Fear of addiction in clinical setting

• Avoiding withdrawal – 20 days or more

• Patient controlled anesthesia (PCA)

• Morphine: DOC - heart attack (MI)

• Meperidine [Demerol]: DOC OB in delivery

• Avoid opioids in Head Injury…

Nursing Implications (ATI p. 133 or 150)

Class: Opioid Agonist- Antagonists (Partial agonist)

|Pentazocine (Talwin) |

|Others: nalbuphine (Nubain), butorphanol (Stadol) |

|MOA |act mostly at mu, kappa receptor to produce analgesia and relieve pain |

| |Alone = agonist action |

| |With agonist = can antagonize (blocks mu receptor) |

|Adverse effects |Similar to opioids |

|ADME (Pharmacokinetics) |Less respiratory depression, low abuse potential |

| |Less effective pain relief |

| |*Can start withdrawal sxms in opioid addiction |

Class: Opioid Antagonists

|Naloxone (Narcan) |

|MOA/ TE/ Use |competes for opiate site and blocks effects of opioid agonists / agonist-antagonists – no significant effect given |

| |alone – resulting in REVERSAL of narcotic |

|ADME |Rebound effect – if you give morphine and narcan- the narcan may wear off first |

|Adverse effects |Acute withdrawal |

|Dosage/ Admin |0.4 mg IM, IV, SubQ |

|Others |Naltrexone (ReVia) ETOH/ Opioid abuse |

Non-Opioid: Centrally Acting Analgesics

|Tramadol (Ultram) |

|Others: clonidine (Duraclon) – pain/ HTN |

|MOA/ TE/ Use |Analog of codeine – binds w mu receptor producing analgesia to relieve pain- also blocks re-uptake of norepi (fight or |

| |flight or increase BP) |

|ADME (Pharmacokinetics) |Minimal potential for dependence or resp depression |

|Adverse effects |Rare – most common: sedation, dizziness, HA, dry mouth, constipation |

|Precautions |Can intensify other CNS dep. – ABSOLUTELY avoid MAOIs |

Ch. 77 Laxatives

Bulk-forming

|Methylcellulose, phyllium (Metamucil) |

|MOA/ Use |Behave like dietary fiber – nonabsorbable – swell to form viscous solution / gel and softening fecal mass and |

| |increasing transit. |

| |Temp relief of constipation, diarrhea, irritable bowel, ostomies |

|Adverse effects |Esophageal & intestinal obstruction if not enough fluid ( ? |

| |(If this, then?) |

| |Can obstruct (build a brick) the gut and won’t move through, therefore causing surgery |

| |Esophagus- if you don’t drink enough to get pill down it can cling to walls and get stuck causing tears |

Surfactants

|Docusate sodium (Colace) |

|MOA/ Use |Lower surface tension of stool and softens by facilitating penetration of water into the feces |

| |Act on intestinal wall to inhibit fluid absorption and stimulate secretion of water and electrolytes into the |

| |intestinal lumen. |

|ADME |Full glass of water |

| |Sit upright for 30 min |

| |Effectiveness dose related (min 200 mg/day) |

|Dosage |50-500 mg daily |

|Adverse reactions |Rare |

|Other |Bring water to the stool to soften it |

| |Typically see someone getting 200+ mg/day |

| |New EBP says that anything under 200 is not effective |

Stimulants

|Bisacodyl (Dulcolax), Senna (Senekot) |

|MOA/ Legitimate Uses |Directly stimulate gut motility, increase secretion of water and ions into intestine, and reduce water and electrolyte |

| |absorption. |

| |Uses: Treatment of (1) opioid-induced constipation and (2) slow transit constipation |

|Dosage |related to formulation administered |

| |Take bisacodyl no sooner than 1 hour after ingesting milk or antacids – do not crush |

|Adverse reactions |bowel rupture can occur |

Osmotics (Salt prototypes)

|Sodium phosphate (Fleet) & Magnesium salts |

|MOA/ Uses |Non-absorbable and retains water in the colon |

|Adverse reaction |Dehydration, diarrhea and loss of water (more with salts than with glycol) |

| |Magnesium can accumulate to toxic levels in renal failure |

| |Sodium can retain fluid – so…. Contraindicated in patients with heart failure HTN and edema |

|Other |glycol (MiraLax) – fewer side effects / safer |

Miscellaneous

• Lactulose- sugar base

– Action / Uses

• Poorly absorbed and cannot be digested – by product of breakdown results in osmotic diuresis

• Enhances excretion of ammonia in liver failure

– SEs – flatulence, cramping

• Glycerin Suppository

• Polyethylene Glycol-Electrolyte (GoLytely)

– Safe in dehydrated or electrolyte sensitive

Additional Nursing Implications

• High risk patients

– Contraindicated in abdominal pain, nausea, cramps, regional enteritis, diverticulitis, ulcerative colitis, acute surgical abdomen, fecal impaction, bowel obstruction.

• Abuse

• Castor oil (powerful stimulant – avoid at night – not to children) p. 908

Ch. 69 Antihistamines

Background

• Histamines – (Predominantly H1)

– Endogenous

– Vessel effects

– Bronchi effects

– Stomach effects

– Greatest interest

• Allergic reactions (mild / anaphylaxis)

• PUD

Histamine Release

• Allergic response

– Requires IgE antibodies

– Prior exposure to allergen

• Non-allergic – direct stimulation of cells

– Some drugs, chemicals, radiocontrast media, plasma expanders - require no prior exposure

– Cell injury

Physio/ Pharm Effects

• H1 Stimulation

– Vasodilation (If this, then?)

– Vessel wall cells contract (If this, then?)

– Bronchoconstriction (If this, then?)

– Itching & pain

– Mucus secretion

– CNS effect – cognition / memory / sleep

• H2 Stimulation

– Secretion of gastric acid (If this, then?)

• H2 blocker, block secretion of acid

Allergies & Pharmacology

• Mild Allergy

– Hay fever, urticaria, mild transfusion rx.

– Sxms caused by ? TX?

• Severe

– Anaphylactic shock (bronchocontriction, hypotension, & edema of glottis)

– Sxms caused by? TX? (ch 17)

• Other Uses

– Common cold – runny nose

|Antihistamines: 1st Generation |

|H1 Antagonists (classic antihistamines) |No single prototype |

| |dyphenhydramine [Benadryl] |

| |Highly sedating |

|MOA |Blockers (1st Gen) |

| |Selectively bind to histaminic receptors |

| |Can also bind to nonhistaminic receptor (muscarinic) |

|TE |Vessels (If blocks histamine, then ?) |

| |Capillaries (If blocks, then ?) |

| |Sensory nerves (If, then) – itching relief |

| |Mucous membranes (If, then) |

| |If you block mucous production, then you get dryness |

| |CNS |

| |Therapeutic doses (If, then) - sedation |

| |Overdose – stimulation, seizures – esp. in young |

| |Other: relieve N & V, motion sickness |

|Clinical uses |Mild allergies, seasonal rhinitis, acute urticaria, allergic conjunctivitis, mild transfusion reactions |

| |Some block muscarinic & H1 receptor sites – useful for motion sickness |

| |promethazine [Phenergan] and dimenhydrinate [Dramamine] |

| |Insomnia (diphenhydramine [Benadryl]) |

|Adverse effects |CNS |

| |Sedation = to excess ETOH (If this, then?) |

| |Dizziness, lack of coordination, confusion |

| |Paradoxical: insomnia, excitation, tremors, convulsions |

| |GI |

| |N, V, Diarrhea / constipation, loss of appetite |

| |Anticholinergic effects (memorize) |

| |Cardiac Dysrhythmias w some 2nd Gen. |

| |Torsades de pointes, V-fib |

| |terfenadine [Seldane] & astemizole [Hismanal] (neither one is on market anymore) |

| |Contraindications – third trimester |

| |Precautions: asthma (bronchoconstriction- spasms), children/elderly, urinary retention, HTN, OA glaucoma, prostatic |

| |hypertrophy |

| |Dry mouth, throat, nasal passages, thickened secretions, (cautions?), urinary histiancy, constipation, palpitations |

|D ( D |ETOH, barbs/benzos/ opioids |

|Toxiciy |Sxms similar to atropine poisoning (anticholinergic), hyperpyrexia (fever) |

| |Can lead to death in children via excitation, hallucinations, convulsion, coma, CV collapse, death. |

| |Tx: remove and support – may use charcoal followed with cathartics |

|Antihistamines: 2nd Generation |

|Prototypes |Fexofenadine (Allegra) – Expensive |

|MOA/ TE |Antagonists of histamine to relieve sxms of allergic rhinitis and urticarias |

|ADME |Do not readily cross B-B barrier therefore non-sedating w minimized anticholinergic SEs |

|Precautions |ETOH, drowsiness, liver, kidneys |

Ch. 75 Drugs for Treating Allergic Rhinitis, Coughs, Colds

|Allergic Rhinitis |

|Review of Sxms |Sneezing, itching, runny nose, congestion |

| |Common- conjunctivitis, sinusitis, asthma |

|Commonly associated disorders | |

|Seasonal vs. Perennial | |

| | |

|Outdoor vs. indoor | |

Antihistamines

• First line - oral

• Prophylaxis first

• No use against cold

• Adverse effects

– 1st gen - sedation, anticholinergic

– 2nd gen - rare

Intranasal Glucocorticoids

|Fluticasone (Flonase) |

|MOA/ Use |Predominantly local anti-inflammatory |

| |First line - Most effective against all sxms |

|Adverse effects |Drying, burning, or itching |

| |Rare - sore throat, epistaxis and HA |

| |Rare - systemic – adrenal suppression / slowed growth in children |

|Dose |Adults – 2 sprays of 50 mcg. once daily |

Intranasal Cromolyn

|Cromolyn (NasalCrom) |

|MOA/ Use |Suppresses release of histamine |

| |Best suited for prophylaxis |

| |May not see results for week or more |

|Adverse effects |Negligible |

Sympathomimetics (Decongestants)

|Phenylephrine (Neo-Synephrine) |

|MOA/ Use |Topical - rapid and intense |

| |Oral - prolonged, moderate, systemic effects |

| |Also used in sinusitis and colds |

|Adverse effects |Rebound congestion |

| |CNS stimulation |

| |Cardiovascular |

| |Hemorrhagic stroke w/ phenylporpanolamine (not on market anymore) |

| |Abuse (pseudoephedrine and ephedrine) |

| |Cocaine |

| |Mimics the synthesetics |

|Nasal sprays |2 – 3 sprays every 4 hours needed – not to exceed 5 consecutive days |

| |Use temporarily |

| |Don’t want tissues to become dependant on it |

| |Don’t want them to think they have to have it for tissues to function |

Anticholinergics

|Ipratropium bromide (Atrovent) |

|MOA/ Use |Blocks cholinergic receptors and inhibits secretions to relieve rhinorrea in allergic rhinitis and asthma |

| |No systemic effects |

|SEs |Drying, irritation |

Leukotriene Antagonist

|Montelukast (Singulair) | |

|MOA/ Use |Blocks binding of leukotrienes to receptors thereby relieving nasal congestion |

|Adverse effects |None significant |

Treatment of Coughs

Antitussives

• Antitussives (cough suppressants)

– Actions / use: elevate cough threshold in common cold and URTI

• Opioid (codeine and hydrocodone) - best

– Dosage: codeine 10 to 20 mg up to 6 times daily

• Nonopioid (dextromethorphan) - best

– Opioid derivative w/o euphoria or dependence

– Can lead to mind-body dissociation equal to PCP

Expectorants

|Guaifenesin (Mucinex) |

|MOA/ Use |Increases flow of respiratory tract secretions |

Mucolytics

|Acetlcysteine (Mucomyst) |

|MOA/ Use |Directly thins secretions |

|ADME |Inhalation delivery |

|Adverse effects |Can trigger bronchospasm |

|Other |antidote for Tylenol |

Colds

• Drug regimen

– Symptomatic

– Combination products

• Decongestants

• Antitussives

• Analgesics

• Antihistamines - anticholinergic to suppress mucus

• Caffeine

Ch. 17 Treatment of Severe Allergy

Adrenergic Agonist

|Epinephrine |

|MOA/ Use |Direct receptor binding (( 1&2, (1&2) mimicing the sympathetic nervous system |

| |Also known as sympathomimetic & catecholamine |

|ADME |Broken down quickly in stomach & significant 1st pass effect (can’t take by mouth) |

| |Can’t cross blood-brain |

| |Discolors (pink/brownish) as it degrades (If, then?) |

|TE |Vasoconstriction (most common use) |

| |Hemostasis |

| |Augments local anesthetic via vascontriction |

| |Elevates blood pressure |

| |Restores beating heart |

| |Bronchodilates |

| |TOC for anaphylactic shock |

| |Mydriasis (rare use) |

|Adverse effects |HTN, necrosis, bradycardia w/ HTN, tachycardia, tremor, chest pain, elevated blood sugar |

|D ( D |MAOIs |

| |TCAs |

| |General anesthestics (myocardial effects) |

|Precautions |IV admin can cause potentially fatal effect – check concentrations! |

| |Insure patent and healthy IV site |

|EpiPen |Anaphylactic deaths |

| |PCN, venoms & foods |

| |Device: EpiPen & EpiPen Jr. |

| |Storage & Replacement |

| |Room temp – dark – do NOT refrigerate |

| |Injection |

| |Dose dependant on weight |

| |Duration |

| |Around 20 min and monitor for 6 hours |

| |SEs- heart rate increase |

Ch. 76 Selected Drugs for Peptic Ulcer Disease (PUD)

Histamine2 – Receptor Antagonists

|Cemetadine (Tagamet) |

|First choice for gastric / duodenal ulcers |

|MAO/ Use |Promote healing through acid reduction |

| | |

| |GERD, Aspiration Pneumonitis in obese & gyne prior to anesthesia |

|Adverse effects |Low incidence of gynecomastia, reduced libido, impotence, CNS depression / excitement, pneumonia |

|D ( D |Inhibits hepatic drug metabolism – therefore? |

| |Major Drugs of concern – warfarin, phenytoin, theophylline, lidocaine |

Table 76-1 (use for histamine and rest of outline)

Famotadine (Pepcid)

• For heartburn, acid indigestion, sour stomach

• Cut dose in renal compromise/ failure

• No antiandrogenic effects

• No effect on hepatic metabolism of other drugs

Proton Pump Inhibitors

|Omeprazole (Prilosec) |

|MOA/ Uses |suppress secretion of gastric acid |

| |Irreversible - days - up to weeks after cessation |

| |Superior to H2RAs |

|Adverse effects |HA, diarrhea, N & V |

| |Long term may increase risk of CA |

|ADME |give 30 min before meal – once daily |

|D(D, D(F |Reduced absorption of atazanavir, ketocanazole and itracanazole – NOT recommended concurrently with atazanavir |

Antacids

|Magnesium hydroxide/ Aluminum hydroxide |

|MOA/ Uses |alkaline agents that neutralize acid & decrease destruction of gut wall |

| |And prophylactically to prevent aspiration pneumonia |

|ADME | Take regularly to promote healing |

| |In PUD: 1 and 3 hr after each meal & at bedtime |

| |Goal is gastric pH greater than 5 |

|Adverse effects |Constipation (aluminum base) / Diarrhea (magnesium base) |

| |Sodium “loading” |

| |High levels in renal failure clients |

|D(D |May interfere with absorption of other drugs |

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