Exam 3 Flashcards
(398 cards)
What is metronidazole
Prodrug that is active against anaerobic bacteria and anaerobic Protozoa
What is the “drug class” of metronidazole
5-nitroimidazoles; includes tinidazole, behave similarly in mechanism, resistance and spectrum; tinidazole is better tolerated
What is the MOA of metronidazole
Relies on activation by susceptible organisms; donates electrons to metronidazole which forms a highly reactive nitro radical anion -> radical mediated DNA damage of organisms; can be recycled by losing electron; O2 can compete with metronidazole (when O2 rises, less likely to be active)
What organisms have developed resistance to metronidazole via increasing levels of O2
T. Vaginalis, G. Lamblia
What are the adverse effects of metronidazole
- metallic taste
- dry mouth
- Nausea
- HA
- disulfiram-like effect (anti-alch medication designed to induce vomiting)
What are the dopamine receptor agonists
Apomorphine, bromocriptine, pramipexole, ropinirole
What are the monoamine oxidase inhibitors
Rasagiline and selegiline
What are the catechism-o-methyltransferase inhibitors
Entacapone and tolcapone
What are the anti-cholinergic drugs
Benztropine, biperiden, orphenadrine, procyclidine, trihexyphenidyl
What do the dopamanergic neurons from the substantia nigra usually do
Inhibit GABAergic output from the striatum (caudate and putamen) (cholinergic has opposite effect)
What can be used to treat PD
Dopamine agonists or anticholinergic drugs
What is levodopa
Immediate metabolic precursor to dopamine
How does levodopa enter the CNS
L-amino acid transporter (LAT); *dopamine cannot cross BBB
What is the MOA of levodopa
Agonist at dopamine receptors
How do you increase the amount of levodopa available to enter the brain
Coadministration with a DOPA decarboxylase inhibitor (carbidopa); does NOT cross BBB
What are the adverse effects of levodopa
- GI: in the absence of carbidopa, causes anorexia, N/V due to activation of chemoreceptor trigger zone
- CV: postural hypotension; when taking large doses or in combo w/ nonselective MAOI/sympathomimetic, can cause HTN
- dyskinesia; choreoathetosis
- behavioral: depression, anxiety, agitation, insomnia, hallucinations, euphoria
- “on-off phenomenon”: give apomorphine to relieve this
What is levodopa contraindicated in
Psychotic patients, angle closure glaucoma, history of melanoma or suspicious skin lesions, active peptic ulcer
What is bromocriptine
D2 agonist, also approved for rx of endocrine disorders; extensive first pass metabolism
What is pramipexole
D3 agonist; approved for treatment of restless leg syndrome; most excreted unchanged in urine; renal insufficiency may require dose adjustment
What is ropinirole
D2 agonist; approved for treatment of RLS
What are the adverse affects of dopamine agonists
- GI: anorexia, N/V; constipation, dyspepsia, reflux
- CV: postural hypotension
- dyskinesia
- mental disturbances
What are contraindications of dopamine agonists
Patients with psych history, recent MI, active peptic ulcer; PVD
What are the two forms of monoamine oxidase
- MAO-A: metabolizes NE and serotonin
- MAO-B: metabolizes phenylethylamine and benzylamine
- dopamine and tryptamine metabolized equally by both
What is selegiline
Aka deprenyl; selective irreversible MAO-B inhibitor (inhibits A at high doses); prolongs affects of l-dopa; contraindicated in patients taking meperidine, tricyclic antidepressants, or serotonin reputable inhibitors