Drugs Test 2 Flashcards
Ceftriaxone (3rd Generation)
MOA: Bind to penicillin binding proteins (transpeptidases) to inhibit cell-wall synthesis
Spectrum: Used for streptococci and more serious gram negative infection. CAN CROSS BLOOD BRAIN BARRIER
Resistance: inactivation of the drug by beta-lactamases
Side affects: allergies
Isoniazid
Inhibits mycolic acids (compnonent of mycobacterial cell wall).
Acetylation by liver varies genetically and fast acetylators may require higher dose.
Rifampin
Inhibits DNA-dependent RNA polymerase induces the formation of drug-metabolizing enzymes including cytochrome p450.
Ethambutol
Inhibits cell wall sythesis by binding arabinosyl
Pyrazinamide
unknown
Amphotericin B
Mechanism: Binds ergosterol creating holes in fungi membrane allowing leakage of electrolytes
Spectrum : Broad; invasive fungal infx in immunocompromised patients. Active against yeast and molds.
Distribution: Liposomal crosses blood brain barrier (large, lipophilic, and acted on by efflux)
Adverse effects: TOXIC because binds cholesterol. Decreases renal blood flow and can lead to permanent destruction of the basement membrane.
Resistance: rare
Flucytosine
Mechanism: Antimetabolite selectively taken up and converted to 5 - FU in fungi, interfering with DNA and RNA sythesis.
Spectrum: Narrow - yeast; Candida Albicans and Cryptococcus
Distribution: Oral, penetrates CNS
Toxicity: Bone marrow suppression - follow patient’s cell counts closely
Resistance: loss of converting enzyme or transporters, COTREAT with Amph B to minimize the develoment of resistance and to increase uptake.
Azoles - Fluconazole, Itraconazole, and Voriconazole
Mechanism - binds fungal p-450 enzyme (Erg 11) and blocks production of ergosterol
Spectrum - Systemic mycoses and yeast
Distribution - Orally available, substrate for efflux pumps in brain (Fluconazole and Voriconazole penetrate CNS)
Toxicity: Drug-Drug interactions, hepatotoxicity, neurotoxicity, alters hormone synthesis. Avoid during pregnancy
ResistanceL Altered cytochrome p-450, upregulation of efflux transporters.
Acyclovir
Antiviral prodrug which is acted on by cellular thymidine kinases to produce acyclovir triphosphate which blocks DNA and RNA chain elongation.
Used for alpha herpes viruses. (A in acylclovir = Alpha)
Gancylcovir
Antiviral prodrug which is acted on by cellular thymidine kinases to produce acyclovir triphosphate which blocks DNA and RNA chain elongation.
Used for beta and gamma herpes viruses. (G gancyclovir= gamma (beta too!)
Sumatriptan
MOA: 5-HT D and B receptor agonist. Causes Vasoconstriction and reduced release of pro-inflammatory neuropeptide (CPRG) release.
Uses: Migraine
Contraindications: Vascular diseases, basilar or hemiplegic migraine, with DHE
Fluoxetine (prozac)
MOA: Selective 5-HT Transport inhibitor (SSRI). Increases Serotonin in synaptic cleft
Uses: Depression, OCD, Panic, PTSD, Phobias
Amitryptaline
MOA: 5-HT transport inhibitor. Increasing serotonin in synaptic cleft. Works as migraine prophylaxis by increasing baseline 5-HT.
Uses: depression etc., MIGRAINE PROPHYLAXIS, and peripheral neuropathy
Side effects: Weight gain, constipation, dizziness, headache, blurred vision.
Drug-drug interactions: Slight interaction with warfarin possible increasing bleeding risk
Dihydroergotamine (DHE)
MOA: Fugal product that acts like triptans ( 5-HT D and B receptor agonist. Causes Vasoconstriction and reduced release of pro-inflammatory neuropeptide (CPRG) release.)
Uses: Migraine management
Side effects: Nausea and vomitting. CYP3A4 rxns.
Contraindicated in vascular, hepatic, or renal disease.
Benzodiazapines
Activate GABA receptors to cause sedation
Baclofen
GABA receptor agonist used as a muscle relaxant.
Strychnine
Antagonist of glycine receptors. Poison that causes intense muscle spasms.
Pregabalin
MOA: Blocks presynaptic VG Ca++ channels
Site of action: presynaptic nocioceptor
Side effects: weight gain, constipation, dizziness, headache, and blurred vision.