Analgesics Flashcards
Mechanism of Opioids…
Modify transmission of pain signals and subjective perception of pain.
Mimic endogenous pain killers (Enkephalins).
Effective, provide a range of durations and variety of routes.
Side effects of Opioids…
N&V, constipation, drowsiness, respiratory depression, hypotension, sedation and dependency.
Cautions / Interactions of Opioids…
Cautions: Acute respiratory depression, alcoholism and head injury.
Interactions: alcohol (sedation, hypotension), Carbamazepine (plasma concentration), Cimetidine (inhibits mechanism).
Types of Receptors…
U = analgesic effects in CNS, spinal cord, peripheral sensory neutrons and GIT. K = sedation/dysphoria.
Pure Agonists =morphine-like drugs, high affinity for U receptors.
Partial Agonist Antagonists = Nalorphine U, Pentazonice O K.
Antagonists = block opiates action, treat heroin/morphine overdose.
Mechanism of Antidepressants…
Mediate descending inhibition of ascending pain pathways in brain/spinal cord.
Treat terminal neuralgia, neuropathic pain - opioid resistant.
Examples of Serotonin/Noradrenaline reuptake inhibitors…
Venlafaxine - diabetic neuropathy.
Duloxetine - peripheral / diabetic neuropathy.
Side effects of Serotonin/Noradrenaline reuptake inhibitors…
Nausea, sedation, headache, dizziness, somnolence, insomnia.
Cautions / interactions of Serotonin/Noradrenaline reuptake inhibitors…
Caution; epilepsy, cardiac diseases, angle closure glaucoma, pregnancy and breast feeding.
Interactions: alcohol, NSAIDS (bleeding), tramadol (CNS toxicity).
Mechanism of Antiepileptic Agents…
Inhibit voltage-gates sodium/calcium channels and glutamate/aminobutyric acid, GABA/glycine receptors.
Inhibit action potential firing, prevent impulse transmission, limit neuronal excitation and enhance inhibition.
Work on descending pathways.
Examples of Antiepileptic Agents…
Carbamazepine - glossopharyngeal neuralgia, post herpetic neuralgia, trigemianal neuralgia and diabetic neuropathies.
Gabapentin - complex regional pain syndrome, deafferentation face neuropathy, postherpetic neuralgia, sciatic pain and neuropathy.
Side Effects of Antiepileptics…
Dizziness, diplopia, drowsiness, fatigue, nausea, hepatotoxicity, renal impairment, skin reactions, anorexia, dyspepsia, tremor.
Cautions / Interactions of Antiepileptics…
Caution; elderly, renal impaired, diabetics, pregnancy, cardiac disease, glaucoma, bone marrow depression.
Interactions; Alcohol.
Mechanism of Local Anaesthetics…
Inhibit voltage gated sodium channels / NMDA receptors, preventing nerve-nervel cell communication, inhibit firing and prevent impulse transmission.
Examples of Local Anaesthetics…
Lidocaine - IV, non cancer patients
Ketamine - blocks glutamate receptors.
Side Effects of Local Anaesthetics…
CNS effects, confusion, respiratory depression, convulsions, hypotension/bradycardia (caine), hypertension/tachycardia (ket)
