Diazepines, oxazepines and thiazepines
Approved by the FDA:
Quetiapine is a dibenzothiazepine atypical antipsychotic. It has been suggested that it's antipsychotic effect is mediated through a combination of dopamine type 2 (D2) and serotonin type 2 (5-HT2) antagonism. It is an antagonist at multiple neurotransmitter receptors in the brain: serotonin 5-HT1A and 5-HT2, dopamine D1 and D2, histamine H1, and adrenergic alpha1- and alpha2-receptors; but it showed no significant affinity at cholinergic muscarinic and benzodiazepine receptors. Norquetiapine, an active metabolite, differs from its parent molecule by having high affinity for muscarinic M1 receptors.
Antagonism at receptors other than dopamine and 5-HT2 with same receptor affinities may demonstrate some of the other effects of quetiapine. The drug's antagonism of histamine H1-receptors may explain the somnolence . The drug's antagonism of adrenergic alpha1-receptors may explain the orthostatic hypotension .
- Discuss specific use of drug and side effects with patient. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
- Patient may experience presyncope, fatigue, blurred vision, illogical thinking, dizziness, headache, hypertension, hyperlipidemia, hypertriglyceridemia, nervousness and anxiety, constipation, xerostomia, weight gain, or hyperglycemia. Have patient report immediately to prescriber angina, significant change in balance, tremors, severe asthenia, polyuria, polydipsia, weight loss, menstrual irregularities, pregnancy, or rash .
- Tell the patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: These are not all side effects. Patient should consult prescriber for additional questions.
- Intended use and disclaimer: Should not be given to patients. This information serves as an initial reference for healthcare providers to use when discussing medications with a patient. You must rely on your own experience and judgment in diagnosing, treating and advising patients.