Pharmacology and Neurological Treatment
Drug Classes to Know
Match drugs to mechanisms. Antiepileptics (phenytoin, levetiracetam, valproate) stabilize neuronal membranes; know phenytoin's narrow therapeutic index and the need for level monitoring. Parkinson therapy centers on levodopa-carbidopa, with carbidopa blocking peripheral conversion to increase CNS delivery; watch for dyskinesias and the on-off phenomenon. Multiple sclerosis uses corticosteroids for acute relapses and disease-modifying agents for long-term control.
Thrombolytics (alteplase) are time-critical in ischemic stroke and require strict exclusion criteria. Anticoagulants and antiplatelets are used for secondary prevention. Migraine treatment includes abortive triptans and preventive agents. Corticosteroids reduce edema in tumors and inflammation. Know reversal strategies and monitoring parameters - for example, INR for warfarin and platelet counts for heparin.
Traps
Questions often test that carbidopa does not cross the blood-brain barrier and only blocks peripheral decarboxylation. Another trap asks which drug is contraindicated in acute hemorrhage (thrombolytics). Watch for phenytoin level questions - toxicity causes nystagmus, ataxia, and confusion. Also remember that abruptly stopping antiepileptics can precipitate seizures.
Rule of Thumb
"Match the drug to the receptor and the patient to the exclusion criteria." For any thrombolytic question, check the time window and bleeding risk first.