Pharmacology: Quiz 3

It binds to Beta subunit of bacterial DNA dependent RNA polymerase and inhibits RNA synthesis.

Broad spectrum with activity against most gram-(+) organisms, Nesseria species, and mycobacteria, including M. tuberculosis.
3) Penetrates into phagocytes, inflamed meninges and excreted through liver into bile.
4) It is used in combo with other drugs for the tx or most atypical mycobacteria.

1) Induces cytochrome P450 which increases elimination of numerous drugs such as

a) oral contraceptives
b) protease inhibitors (HIV meds)
c) Corticosteroids

1. Allergic reactions, include rash or fever in up to 2% of pts.
• induced hepatitis is most frequent major toxic effect (1%) while 10-20% have minor increases in liver transaminases **
Clinical hepatitis (1%) increases with age after age 35, pregnancy and postpartum and requires immediate d/c of drug
Check baseline LFTS and periodically during therapy for high risk patients.


• Peripheral neuropathy 10-20% in higher doses above 5mg/kg/day which can be avoided by administration of pyridoxime Vit B6. More common in malnourished, alcoholic, diabetics, pregnant women.

MC is Retobular neuritis ("E" for Eyes)
1. Lost of color vision Green >red
2. Lost of visual acuity

–1-5% of patient depending on dosage
•Periodic VA testing is recommended for doses of 25mg/kg/day for several months
–Red-green color discrimination

Several months after starting tx, dose dependent adverse effects related to Optic Neuritis

–Isoniazid* most active (given with Vit. B6)
–Rifampin* most active
–Pyrazinamide (PZA)
–Ethambutol
–Streptomycin

Active TB
4 drug regimen with INH, RIF, PZA and Ethambutol plus Vit B6 for 2 full months (initiation phase, the killing phase), sx resolve and pts become non-infectious. Followed by 18 weeks (continuation phase, eliminates persistent organisms or semi dormant bugs) of INH and RIF.

Broadest spectrum antifungal DRUG OF CHOICE FOR LIFE THREATENING fungal infections.

MOA: binds to ergosterol in fungal cell membrane and alters permeability= forms pores.

Antifungal tx of crytococcal meningitis:
• Amphotericin B for severe disease

1) AMPHO: “TERRIBLE” infusion related
2) 50% pts get fever, chills, muscle spasms, HA, hypotension
3) SLOWER TOXICITIES: IMPAIRED RENAL FUNCTION, 80%, renal damage very common – dose limiting.

1) MILD TO MOD= FLUCONAZOLE(diflucan) long term treatment. Penetrates the CSF and is the DRUG OF CHOICE for acute and maintenance treatment of Cryptococcal meningitis.
2) AMPHOTERICIN B= FOR SEVERE DISEASE

1. GI side effects are most common
2. hepatotoxicity therefore liver must be monitored (LFT)”BLACK BOX WARNING”
3. Endocrine: Interferes with synthesis of hormones; may lead to infertility, impotence, gynecomastia (development of abnomally large mammary glands in males), and menstrual irregularity

Serious rxn are seizures, hepatotoxicity. Common rnx are n/d/v, H/A, GI problems, dizziness, rash.

1. Is the only azole drug to penetrate CNS; use for tx of candida infx and cyrtpccocal meningitis

1. hepatotoxicity (most monitor LFTs)
2. GI
3. rash
4. Edema
5. EXTRA INFO: black box warning: negative inotropic effect, must avoid use if CHF

1. elevated LFT (elevated liver enz)
2. rash
3. visual disturbances
4. GI , N/V/D

Fluconazole (traizole antifungal); PO

Dyslipidemia-Dyslipidemia is elevation of plasma cholesterol, triglycerides (TGs), or both, or a low high density lipoprotein level that contributes to the development of atherosclerosis.


BAS are “second most effective” in lowering LDL and may be added to statin to achieve LDL goals. Remember that most effective drug for lowering LDL is statin

Mainly GI :
-constipation
-bloating
-fullness
-nausea
-flatulence (“passing gas”)
DO NOT USE:
-do not use in pt’s with high TG ( may increase VLDL and TG )