GI: ANTIEMETICS - PHENOTHIAZINES Flashcards
1
Q
ANTIEMETICS PHENOTHIAZINE: INDICATIONS
A
- Prophylaxis and Tx of Nausea and Vomiting - particularly when due to vertigo
- Psychotic disorders (eg Schizophrenia) - 1st gen Antipsychotics
2
Q
ANTIEMETICS PHENOTHIAZINE: MOA
A
- Blockade of various receptors (D2 in the CTZ and gut), lesser extent H1 and Ach (Muscarinic) receptors in the vomiting and vestibular system
- Effective for nausea and vomiting in a variety of settings (eg chemo, radio therapy, vertigo)
3
Q
ANTIEMETICS PHENOTHIAZINE: ADVERSE EFFECTS
A
- Drowsiness and postural hypertension
- Movement abnormalities (eg EXTRAPYRAMIDAL SYNDROMES - arising from D1 receptor blockade)
- Acute dystonic rxn (such as an oculogyric crisis) - ST
- Extrapyramidal syndromes (TARDIVE DYSKINESIA)
- QT-interval prolongation
4
Q
ANTIEMETICS PHENOTHIAZINE: WARNINGS
A
- Sedative effect
- Potential for hepatotoxicity -> avoided in severe liver dx patients
- Avoided in patients susceptible to anticholinergic SEs - PROSTATIC HYPERTROPHY ( who may develop urinary rtn)
- Reduced doses in the elderley
5
Q
ANTIEMETICS PHENOTHIAZINE: INTERACTIONS
A
- Extensive list of interactions, consult the BNF
- Drugs that prolong QT interval (eg antipsychotics, amiodarone, ciprofloxacin, maroclides, quinine, SSRIs)
6
Q
ANTIEMETICS PHENOTHIAZINE: EXAMPLES
A
- Prochlorperazine
- Chloropromazine