Pharmacology Mnemonics - Flash Cards

Name: Dextromethorphan

Class: Opioid (Semi-synthetic) (OTC)

Mechanism: Agonist of opioid receptors ® depression of CNS cough center.

Absorption: Oral.

Metabolism.: Hepatic conjug. ® polar Metabolismolites.

Excretion, t½: Urine.

Toxicity/S.E.s:High doses ® hallucinations. Potentially fatal interactions with MAOIs.

Utility: Antitussant.

Special Features: Minimal addiction/abuse liability.

Name: Heroin

Class: Opioid (Semi-synthetic)

Mechanism: Agonist of opioid receptors. Causes analgesia (­ threshold for pain, ¯ subjective rxn), antitussive effects, euphoria/dysphoria (atypical), sedation (rarely stimulation), resp. depression, miosis, n/v, ¯ body temp., ­ ACTH/PRO/GH, ¯ LH/TSH (hormone effects usu. non-consequential), occasionally hypotension, constipation, ­ biliary/ureteral/bladder muscle tone, ¯ uteral muscle tone, histamine release (hypotension, urticaria, itching). Init. ¯ of adenylate cyclase in locus coeruleus & symp. pregang. neurons. Tolerance develops.

Absorption: IM, subcut., mucous membranes, oral, smoking.

Metabolism.: Hepatic conjug. ® polar Metabolismolites. Excretion, t½: Urine.

Toxicity/S.E.s: Histamine release ® asthma in suscept. patients. Use w/caution w/compromised resp. patients. CO2 retention ® ­ intracranial pressure (may mask signs of head injury). Poisoning ® coma, severe resp. depression, pinpoint pupils. Rapid onset of tolerance (up to 100x) to analgesia, euphoria/dysphoria, sedation, n/v, resp. depression, cough suppression. Physical dependence—abrupt w/drawal (prob. med. by hyperactive adenylate cyclase) ® rhinorrhea, lacrimation, chills, goose pimples, hyperventilation, mydriasis, myalgia, vomiting, diarrhea, anxiety, hostility (but it’s not fatal). Also psychological dependence. Drug interactions—sedative hypnotics ® severe CNS/resp. depression; phenothiazines/tricyclic antidepressants ® ­ sedation, freq. resp. depression.

Special Features: High addiction/abuse liability. Psych. dependence.

Name: Codeine

Class: Opioid (Alkaloid)

Mechanism: Agonist of opioid receptors. Causes analgesia (­ threshold for pain, ¯ subjective rxn), antitussive effects, euphoria/dysphoria (atypical), sedation (rarely stimulation), resp. depression, miosis, n/v, ¯ body temp., ­ ACTH/PRO/GH, ¯ LH/TSH (hormone effects usu. non-consequential), occasionally hypotension, constipation, ­ biliary/ureteral/bladder muscle tone, ¯ uteral muscle tone, histamine release (hypotension, urticaria, itching).

Absorption: IM, subcut., mucous membranes, oral (high oral:parenteral potency).

Metabolism.: Hepatic conjug. ® polar Metabolismolites.

Excretion, t½: Urine. Duration of analgesia—3-4 hr.

Toxicity/S.E.s: Histamine release ® asthma in suscept. patients. Use w/caution w/compromised resp. patients. CO2 retention ® ­ intracranial pressure (may mask signs of head injury). Poisoning ® coma, severe resp. depression, pinpoint pupils. Rapid onset of tolerance (up to 100x) to analgesia, euphoria/dysphoria, sedation, n/v, resp. depression, cough suppression. Physical dependence—abrupt w/drawal ® rhinorrhea, lacrimation, chills, goose pimples, hyperventilation, mydriasis, myalgia, vomiting, diarrhea, anxiety, hostility (but it’s not fatal). Also psychological dependence. Drug interactions—sedative hypnotics ® severe CNS/resp. depression; phenothiazines/tricyclic antidepressants ® ­ sedation, freq. resp. depression.

Utility: Antitussant. Analgesia.

Name: Morphine

Class: Opioid (Alkaloid)

Mechanism: Agonist of opioid receptors. Causes analgesia (­ threshold for pain, ¯ subjective rxn), antitussive effects, euphoria/dysphoria (atypical), sedation (rarely stimulation), resp. depression, miosis, n/v, ¯ body temp., ­ ACTH/PRO/GH, ¯ LH/TSH (hormone effects usu. non-consequential), occasionally hypotension, constipation, ­ biliary/ureteral/bladder muscle tone, ¯ uteral muscle tone, histamine release (hypotension, urticaria, itching).

Absorption: IM, subcut., mucous membranes, intrathecal, oral (1st pass Metabolism ® low oral:parenteral potency)

Metabolism.: Hepatic conjug. ® polar Metabolismolites.

Excretion, t½: Urine. Duration of analgesia—4-5 hr.

Toxicity/S.E.s: Histamine release ® asthma in suscept. patients. Use w/caution w/compromised resp. patients. CO₂ retention ® ­ intracranial pressure (may mask signs of head injury). Poisoning ® coma, severe resp. depression, pinpoint pupils. Rapid onset of tolerance (up to 100x) to analgesia, euphoria/dysphoria, sedation, n/v, resp. depression, cough suppression. Physical dependence—abrupt w/drawal ® rhinorrhea, lacrimation, chills, goose pimples, hyperventilation, mydriasis, myalgia, vomiting, diarrhea, anxiety, hostility (but it’s not fatal). Also psychological dependence. Drug interactions—sedative hypnotics ® severe CNS/resp. depression; phenothiazines/tricyclic antidepressants ® ­ sedation, freq. resp. depression.

Utility: Analgesia. Intrathecal for post-surg. pain ® long duration of action, few side effects.

Special Features: High maximum efficacy. High addiction/abuse liability. Psych. dependence.

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.