General Pharmacology Flashcards
Which medications cause drug induced lupus?
- Hydralazine
- Procainamide
- Isoniazid
- Minocycline
- Quinidine
What are the signs and symptoms of drug induced lupus?
- New onset lupus symptoms
- Such as low grade fever, multiple joint pains and erythematous rash
- Anti-nuclear antibodies (ANA) and antihistone antibodies present in >95%
- Anti-dsDNA antibodies rarely seen
- Slow acetylators are at increased risk
How do you differentiate SLE from DILE?
DILE - Anti-histone antibodies in >95% - Antinuclear antibodies seen SLE - Anti-dsDNA antibodies present in 80% - Anti-histone antibodies seen in 50% - Antinuclear antibodies seen
What is the beers criteria?
- Medications that should be avoided in the elderly Anti cholinergics > First generation antihistamines > Gastrointestinal spasmodics Cardiovascular > Alpha 1 blockers Central Nervous System > Tricyclic Antidepressants > Antipsychotics >Barbiturates, Benzodiazepines, Hypnotics Endocrine > Long acting sulfonylureas > Sliding scale insulin Pain > Non-selective NSAIDs > Skeletal Muscle Relaxants
What is accuracy and what is precision?
Precision (reliability)
- The ability of the test to reproduce identical or similar results with repeated measurements
Accuracy (validity)
- The ability of a test to measure what it is supposed to measure
- Its results have to be equivalent to the results obtained with the gold standard
What is the mechanism of action of benzodiazepines?
- GABA is the main inhibitory neurotransmitter in the CNS
- Benzodiazepines act on the GABAa receptor complex
- They bind to the benzodiazepine binding site
- Allosterically modulates the binding of GABA
- Results in increased frequency of chloride ion channel opening
- Influx of chloride into ions causes neuronal hyperpolarization and inhibition of the action potential
What is the mechanism of action of cephalosporins?
- Beta lactam antibiotics, contain beta lactam ring
- They irreversibly bind penicillin binding proteins such as transpeptidases
- Inhibit cell wall synthesis but less susceptible to penicillinase
- Bactericidal (kill bacteria)
What is the mechanism of action of penicillins?
- Beta lactam antibiotics, contain beta lactam ring
- Irreversibly bind penicillin binding proteins such as transpeptidases
- Block transpeptidase cross-linking of peptidoglycan in cell wall preventing cell wall synthesis
- Activate autolytic enzymes (lyse cell wall)
What are the penicillinase sensitive penicillins?
- MOA
- Uses
- Side effects
- Resistance
Amoxicillin, Ampicillin; Aminopenicillins
MOA: Bind penicillin binding proteins (transpeptidases) preventing cell wall synthsis. Are penicillinase sensitive. Are combined with clavulonic acid to protect against destruction by Beta-lactamase
Uses: Extended spectrum penicillin
- H. influenzae
- H. pylori
- E.coli
- Listeria
- Proteus
- Salmonella
- Shigella
Side effects: Hypersensitivity; rash, pseudomembranous colitis
Resistance: Penicillinase in bacteria (Beta-lactamase) that cleaves the beta lactam ring
What is the mechanism of action of azoles?
- Antifungal medications that inhibit the demyelination of lanosterol into ergosterol in fungal cells
- Therefore suppress synthesis of ergosterol, essential to the fungal cell membrane
- Also inhibit the P-450 cytochrome oxidase system leading to drug interactions due to their increased levels in the blood and toxicity
Which drugs induce or rev up the P-450 cytochrome oxidase system?
Rifampin Phenytoin Carbamazepine Phenobarbitol Griseofulvin
What is the mechanism of action of Griseofulvin?
- Enters fungal cells and binds microtubules, inhibiting mitosis
What is the mechanism of action of flucytosine?
- Inhibits fungal DNA synthesis (replication) and RNA synthesis (protein)
- Used synergistically with amphoteracin B
- Treats cryptococcal meningitis
What is the mechanism of action of Caspofungin?
- Blocks glucan synthesis
- 1,3-beta-D-glucan is a major polysaccharide component of the fungal cell wall
What is the mechanism of action of amphoteracin B?
- A polyene antifungal that binds ergosterol in the fungal cell membrane leading to pore lysis
