Neurological Flashcards
Levodopa (Co-beneldopa, Co-careldopa, Sinemet, Madopar)
Dopamine precursor
Mechanism of Levodopa
Levodopa crosses blood-brain barrier to basal ganglia and is converted to dopamine by dopa carboxylase
Indications of Levodopa
Parkinsons Disease
Contraindications of Levodopa
Closed-angle glaucoma Drug-induced parkinsonism Psychiatric disease or dementia Cardiac or cerebrovascular disease Diabetes Pregnancy
Side-effects of Levodopa
Nausea, palpitations, anorexia, vomiting, abdominal pain, insomnia, agitation, postural hypotension
Interactions of Levodopa
MAOIs: risk of HT (withdraw L-dopa 2 weeks before starting MAOIs)
Iron: reduced absorption of L-dopa
Antipsychotic drugs: reduce effect of L-dopa
What is Levodapa prescribed with and why
Carbidopa. Prevents levodopa from being converted into dopamine prematurely in the bloodstream, allowing more of it to get to the brain
Phenytoin (Fosphenytoin, Epantuin)
Anti-seizure
Mechanism of Phenytoin
Inhibits initiation of action potentials in the brain resulting in seizure control
Indications for Phenytoin
Epilepsy
Migraine
Trigeminal Neuralgia
Abnormal heart rhythms
Contraindications for Phenytoin
Pregnancy- Drug is teratogenic
Diabetes
Porphyria
Hepatic Impairment
Side effects of Phenytoin
Nausea and vomiting, confusion, insomnia, hirsutism
Rare: rash, gum hypertrophy, Stevens-Johnson syndrome
Interactions of Phenytoin
OCP: Phenytoin reduces effectiveness
Rifampicin: decrease concentration of Phenytoin
Warfarin: increase metabolism of warfarin
Antidepressants, antipsychotics, mefloquine, chloroquine and St. John’s Wort
Carbamazepine (Carbagen, Epimaz, Tegretol)
Anti-convulsant
Mechanism of Carbamazepine
Increases GABA-mediated inhibitory transmission
Indications of Carbamazepine
Generalised tonic-clonic seizures Partial seizures Trigeminal neuralgia Bipolar prophylaxis Reduce urine output in diabetes insipidus Relieve pain in diabetic neuropathy
Contraindications of Carbamazepine
Bone marrow depression
AV node conduction abnormalities
Porphyria
Side effects of Carbamazepine
Drowsiness, ataxia, blurred vision, confusion
Interactions of Carbamazepine
Cimetidine, erythromycin: inhibit metabolism of carbamazepine
Corticosteroirds, cyclosporine, phenytoin: decrease effect of Carbamazepine
Diltiazem, Isoniazid, Verapamil: increase plasma concentration
OCP
Warfarin
Sodium Valporate
Anti-convulsant
Mechanism of Sodium Valporate
Increase GABA content of the brain by inhibiting GABA transaminase enzyme, preventing GABA re-uptake
Indications of Sodium Valporate
Epilepsy (all types)
Manic episodes
Bipolar Disorder
Contraindications of Sodium Valporate
Hepatic dysfunction
Porphyria
Blood disorders
Pregnancy
Side effects of Sodium Valporate
Hair loss, weight gain, Nausea and vomiting
Interactions of Sodium Valporate
Anticonvulsants, Zidovudine, Lamotrigine, Carbapenems, Antidepressants, antipsychotics, clarithromycin and erythromycin
Lamotrigine (Lamictal)
Anti-convulsant
Indications of Lamotrigine
Epilepsy
Lennon-Gastaut syndrome seizures
Trigeminal neuralgia
Side effects of Lamotrigine
Skin rash, nausea, headache, dizziness and poor muscle coordination
Interactions of Lamotrigine
Sodium Valporate
Antidepressants, antipsychotics, rifampicin, mefloquine and chloroquine
Carbamazepine
Phenytoin and phenobarbital
Levetiracetam (Keppra)
Anticonvulsants
Indications of Levetiracetam
Focal Seizure Epilepsy
Contraindication of Levetiracetam
Anaemia
Psychotic disorder
Depression
Liver or kidney disease
Side effects of Levetiracetam
Headache, dizziness, drowsiness, GI problems, anxiety, asthenia
Interactions of Levetiracetam
MAOIs, TCA, SSRIs and Mefloquine
St John’s Wort
Mefloquine
Anti-malarial drug. Effective against malaria parasites resistant to chloroquine
