Neuro Medications Overview part 1

Neuro Medications

• Dopamine Agonists (Dopaminergics): Reduce tremors and muscle rigidity in Parkinson's Disease. Mechanism involves promoting dopamine synthesis, activating dopamine receptors, preventing dopamine breakdown, or decreasing levodopa degradation. Adverse effects include CNS effects, peripheral effects, bone marrow depression, and hepatic dysfunction. Examples include levodopa/carbidopa (Duopa), pramipexole (Mirapex).

• Anticholinergics: Used for extrapyramidal side effects of antipsychotic medications. Enhance dopamine/acetylcholine balance by blocking acetylcholine effects. Have greater affinity for CNS receptors than peripheral receptors. Adverse effects include CNS effects, peripheral anticholinergic effects (tachycardia, palpitations, hypotension), urinary retention and hesitancy. Example: benztropine (Cogentin).

• Indirect-Acting Cholinergic Agonists: Slow memory loss and cognitive decline in early Alzheimer's stages and Myasthenia Gravis. Mechanism involves blocking acetylcholinesterase to allow acetylcholine accumulation at nerve endings, thus stimulating parasympathetic functions. Note that the impact on the nervous system is similar to stimulating cholinergic function.

Alzheimer's Disease and Myasthenia Gravis

• Mechanism: Block acetylcholinesterase at the synaptic cleft, allowing acetylcholine accumulation from nerve endings, thus stimulating parasympathetic nervous system.

• Effects: Increased acetylcholine levels may lead to gastrointestinal (Gl), cardiovascular (CV), and urinary tract effects.

Migraines

• Ergot Derivatives: Block alpha-adrenergic and serotonin receptor sites to constrict cranial vessels, decreasing cranial artery pulsation and hyperperfusion of the basilar artery. Effects include CNS effects (dizziness, vertigo, tingling sensation), CNS effects (hypertension, abdominal pain, nausea and vomiting). Examples include ergotamine, sumatriptan.

• Triptans: Bind to selective serotonin receptor sites to constrict cranial vessels. Effects include CNS effects (drowsiness, headache, paresthesia), GI effects (dry mouth, nausea, abdominal pain, dysphagia), CV effects (coronary artery vasospasm, MI, ventricular arrhythmias). Examples include almotriptan, eletriptan.

• CGRP Inhibitors: Inhibit CGRP, a vasodilator released during migraine attacks. Examples include lasmiditan. Possible side effects include dizziness, fatigue, paresthesia, sedation, and hypersensitivity reactions.

• Serotonin Agonists: Have a specific action on serotonin receptors. Possible side effects include nausea and injection site reactions.

Epilepsy

• Hydantoins: Stabilize nerve membranes throughout the CNS, impacting ionic channels, reducing excitability and hyperexcitability. Possible side effects include cellular toxicity (severe liver toxicity, bone marrow suppression, gingival hyperplasia), and dermatological issues (potentially serious, or frank malignant lymphomas). Examples include phenytoin (Dilantin), fosphenytoin (Cerebyx, Sesquient).

• Barbiturates: Inhibit impulse conduction in ascending RAS, suppressing cerebral cortex, cerebellar function, and motor nerve output. Stabilize nerve membranes, decreasing excitability and hyperexcitability. Possible side effects include CNS depression, cellular toxicity (severe liver toxicity), bone marrow suppression, and derm issues (gingival hyperplasia, potentially serious dermatological reactions, frank malignant lymphoma). Example: Phenobarbital (Solfoton, Luminal).

• Benzodiazepines: Enhance GABA, possibly impacting CNS depression and physical dependence/withdrawal symptoms. Example: alprazolam (Xanax).

Immune Suppressants

• Multiple Sclerosis: The mechanism of action isn't fully understood, but effects may include suppressing inflammatory system responses, with specific effects varying by drug. Side effects can include symptoms such as dizziness, weakness, fatigue, agitation, anxiety, and, rarely, suicidal thoughts.

General Information

• GABA Modulators: Valproic acid and divalproex reduce abnormal brain electrical activity potentially by acting on GABA receptors. Acetylzolamide and Zonisamide may alter electrolyte movement and influence voltage-sensitive sodium/calcium channels. General CNS effects like those seen with other medications (dizziness, drowsiness) are possible across classes.