Pharmacology Mnemonics - Flash Cards

Name: Diphenhydramine (Benadryl)

Class: H₁-Histamine Antagonist (OTC)

Mechanism: Competitive inhib. of histamine and histamine receptor interaction.

Absorption:

Dist.: Enters CNS

Excretion, t½:

Toxicity/S.E.s: Sedation (not in everyone). Taken w/alcohol ® enhanced CNS depression. Local anesthetic activity. Acute poisoning in kids ® complex CNS excitatory and depressant effects (convulsions, hyperpyrexia). Topical use = highest risk of sensitization, \ shouldn’t be applied topically.

Utility: Treat allergic rxns (e.g., hay fever). Prevent motion sickness. Can be used for morning sickness. Treat PD symptoms (esp. geriatric patients).

Special Features: Most effective if taken prophylactically. Can’t reverse effects once histamine has bound to receptor. Therapeutically effective dose related to amount of antigen.

Name: Zolpidem (Ambien)

Class: Antianxiety-Sedative-Hypnotic Agent

Mechanism: Binds to BDZ receptors, although it’s not structurally related to BDZs.

Absorption:

Dist.:

Metabolism.:

Excretion, t½:

Toxicity/S.E.s: Tolerance and physical dependence rarely develop.

Utility: Short-term treatment of insomnia. As effective as BZDs in prolonging total sleep time and shortening sleep latency. Little effect on sleep stages.

Special Features:

Name: Chloral hydrate

Class: Antianxiety-Sedative-Hypnotic Agent

Mechanism: Sim. to barbiturates

Absorption:

Dist.:

Metabolism.:

Excretion, t½:

Toxicity/S.E.s:

Utility: Used in hospitals, nursing homes, pediatric dental settings. Mickey Finn.

Special Features: Rarely used.

Name: Pentobarbital

Class: Antianxiety-Sedative-Hypnotic Agent (Barbiturate)

Mechanism: Potentiates GABA transmission by interacting w/GABA receptor. High doses ® direct activation of Cl^- channel ® global CNS synaptic depression.

Absorption:

Dist.:

Metabolism.: Hepatic Metabolism ® inactive Metabolismolites. Signif. induction of hepatic microsomal enzymes ® ­ potential for drug interactions.

Excretion, t½:

Toxicity/S.E.s: Dose-dependent depression of CNS fxn (mild sedation ® sleep ® coma ® coma w/resp. depression ® death). Chronic use of doses 2x-4x hypnotic dosage ® tolerance & psych/phys. dependence. W/drawal symptoms include grand mal seizures and DTs and are potentially lethal.

Utility: Rarely used as backup to other sedative-hypnotic drugs. Suicide.

Special Features: Short-acting agent

Name: Phenobarbital

Class: Antianxiety-Sedative-Hypnotic Agent (Barbiturate) (Antiepileptic:Tonic-Clonic)

Mechanism: Potentiates GABA transmission by interacting w/GABA receptor ® ­ duration of channel opening. High doses ® direct activation of Cl^- channel ® global CNS synaptic depression & block of sustained high freq. repetitive firing..

Absorption:

Dist.: 40-60% protein binding.

Metabolism.: Hepatic Metabolism ® inactive Metabolismolites. Signif. induction of hepatic microsomal enzymes ® ­ potential for drug interactions.

Excretion, t½: 46-136 hr (adults), 37-173 hr (kids).

Toxicity/S.E.s: Dose-dependent depression of CNS fxn (mild sedation ® sleep ® coma ® coma w/resp. depression ® death), cognitive impairment, hyperactivity, ataxia, changes in sleep patterns. Non-dose-rel.—lethargy, ¯ attention span, osteopenia. Idiosync.—allergic dermatitis, Stevens Johnson synd., serum sickness rxn, granulocyte suppress. Chronic use of doses 2x-4x hypnotic dosage ® tolerance & psych/phys. dependence. W/drawal symptoms include grand mal seizures and DTs and are potentially lethal.

Utility: Alt. treatment for gen. tonic-clonic & partial seizures. Alt. treatment of status epilepticus. Rarely used as backup to other sedative-hypnotic drugs. Suicide.

Special Features: Long-acting agent