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Flashcards in Drugs on Exam 3 Deck (17):
1

Carbidopa

Parkinson’s
Dopamine Precursors / DDC inhibitors

2

Levodopa/Carbidopa

Parkinson’s
Dopamine Precursors / DDC inhibitors

Endogenous precursor to DA. Very short acting; peak action 30-60min, cleared in 2 hours

L-DOPA is an intermediate produce in the synthesis of dopamine endogenously. Since Parkinson’s is a disease of too little dopamine synthesis, giving L-DOPA can help replenish some of the missing dopamine in the brain. Carbidopa cannot cross the BBB but can inhibit degradation of L-DOPA in the guy and liver by blocking dopamine decarboxylase. Thus, by giving L-DOPA with carbidopa, you can deliver a high dose of L-DOPA to the brain where it can be converted to dopamine in the basal ganglia.

ADRs: Acute nausea, hypotension, depression, and psychosis
Chronic dyskinesia and psychosis

3

Anticholinergic Drugs

Parkinson’s

When there is loss of dopamine, there is over-activity of cholinergic interneurons in the putamen and caudate (DA inhibits ACh). The anticholingerics used in Parkinson’s block muscarinic receptors. These drugs are less effective than L-DOPA, but are sometimes used as initial therapy for tremor. However, side effects make these drugs difficult to tolerate.

4

Monoamine Oxidase Inhibitors

Parkinson’s

MAO is responsible for breaking down dopamine into DOPAC. By inhibiting this action, the effects of dopamine (and L-DOPA) can be potentiated. There are two types of MAO A and B. MAO-A has dangerous side effects because it affects the breakdown of many different monoamines (EPI, NE, 5HT, DA), limiting therapeutic use to MAO-B inhibitors, which are dopamine specific

5

Catechol-O-Methyltransferase Inhibitors

Parkinson’s

COMT is also part of the metabolism pathway of L-DOPA and dopamine. Giving COMT inhibitors can potentiate the effects of these molecules, making L-DOPA dosing less frequent.

6

Prostaglandin analogs

Glaucoma
ie Latanoprost

*Lower IOP by facilitating aqueous humor outflow through accessory uveosclero pathway
*First-line therapy in open-angle glaucoma as part of stepped approach
*Side effects include brown discoloration of iris, eyelash lengthening, and ocular irritation

7

Alpha-2 adrenergic agonists

Glaucoma
ie. Brimonidine

*Increases uveoscleral outflow pathway and inhibits aqueous humor production
*Add-on 2nd or 3rd line therapy in open-angle glaucoma
*Side effects include red eye, ocular irritation, CNS depression and apnea in neonates

8

Beta-adrenergic antagonists

Glaucoma
ie Timolol

*Reduces aqueous humor production
*Next most common drug used for open-angle glaucoma after prostaglandin analog
*Side effects include systemic absorption leads to decreased HR, bronchoconstriction, etc
*CONTRAINDICATED in Pts with bradycardia, heart block, CHF, asthma and COPD

9

Carbonic anhydrase inhibitors

Glaucoma
ie Dorzolamide

*Inhibiting CA in ciliary body epithelium reduces bicarb ion formation, leading to reduced fluid transport and IOP
*Add-on 2nd or 3rd line in open-angle glaucoma
*Side effects are few if applied topically

10

Cholinergic Receptor Agonists

Glaucoma
ie Pilocarpine

*Lowers IOP through contraction of ciliary muscle (increases aqueous outflow)
*Used in treatment of closed-angle glaucoma
*Not commonly used today for open-angle glaucoma
*Side effects include Ciliary spasm leading to HA, myopia, dim vision

11

tetrabenazine

Tourette syndrome and Huntington’s disease

Dopamine depleting drug

12

neuroleptics-aka dopamine receptor antagonist

Tourette syndrome and Huntington’s disease

Fluphenazine, aripiprazole

Side effects: weight gain, sedation

13

primidone

Essential tremor

14

propranolol

Essential tremor

15

Ropinirole

Parkinson's
Dopamine Receptor Agonist

D2 receptor agonist (also D3 and D4)

ADRs: Nausea, Changes in mentation, Sudden onset of sleep

16

Amantadine

Parkinson's

Glutamate Receptor Antagonist

Increases availability of endogenous DA in caudate and putamen

17

Pramipexole

Parkinson's
Dopamine Receptor Agonist

D2 receptor agonist (also D3 and D4)

ADRs: Nausea, Changes in mentation, Sudden onset of sleep