- sedatives

- alcohol

- analgesics

- antihistamines

2. Opioids - increase in analgesic action, sedation ; increase in respiratory depression 

-morphine

-meperidine

3. l-DOPA - inhibit action of precursor and agonists

Bromocryptine

4. Guanethidine - decreased antihypertensive effect(CPZ

                           due to decrease transport of    Guanethidine into nerve

5. Antihypertensive agents - -increase risk of postural hypotension (CPZ)

6. Digitalis - Thioridazine: decrease in quinidine-like action of digitalis => myocardial depression, increase in risk of tachycardia

7. TCAs, Antiparkinson agents - - enhanced anticholinergic effects => confusion, delirium

8. Barbiturates, Anticonvulsants - - enhanced metabolism of APDs

9. Insulin, oral hypoglycemics - - poor control of diabetic symptoms.CPZ=> increase in blood glucose

10. Antacids - - decrease in absorption from G.I.T.

11. Amphetamines -  antagonize antipsychotic effects

12. Lithium -  sign. increase in blood levels of APD

- CPZ: will mask signs of early lithium toxicity,i.e., nausea, vomiting