c. Untoward Effects. Sedation and drowsiness are untoward effects in some
instances, but in others they are the effects desired. Other side effects are dryness of
the mouth, skin rash, sensitivity to light, nausea and vomiting, and nasal stuffiness.
Low blood pressure may result, especially when the drug is given intravenously.
Therefore, the client should remain in bed for an hour or two following parenteral
administration. As a rule, these effects do not require that administration of the drug be
stopped. Untoward effects that do require immediate stopping of the drug are the
development of extrapyramidal effects (tremulousness, drooling, muscular rigidity, blank
facial expression, and peculiar, stiff-legged gait), as well as jaundice, fever, sore throat,
leukopenia (too few white blood cells), and anemia.
d. Cautions and Contraindications. The drug is not to be given to a comatose
client. It should be used with caution when given with drugs that it potentiates (such as
ethyl alcohol, morphine, and phenobarbital). Caution in its use should also be observed
for clients in whom a sudden drop in blood pressure is considered dangerous. The
drug should not be used on people who have liver disease.
e. Supply. Chlorpromazine hydrochloride is supplied in 25-mg, 50-mg, and
100-mg tablets; in 150-mg capsules; in 4-fl oz (118-ml) bottles of concentrated, flavored
solution containing 30 mg per ml; and as a solution for injection containing 25 mg per
ml in 2-ml ampules.
3-17. SUMMARY OF RELATED AGENTS
a. The following are phenothiazines with effects very similar to chlorpromazine:
(1) Promazine hydrochloride (Sparine Hydrochloride). The therapeutic
effects of promazine hydrochloride seem to be identical to those of chlorpromazine
hydrochloride, but the toxic effects are apparently less. However, the same degree of
caution should be used.
(2) Thioridazine hydrochloride (Mellaril). This drug produces the same
effects as chlorpromazine hydrochloride, except it does not have an antiemetic effect
and it does not produce extrapyramidal effects (parkinsonism, dystonia, and akathisia)
in ordinary doses.
b. The drugs listed here tend to have more pronounced extrapyramidal and
antiemetic effects than other antipsychotic tranquilizers.
Trifluoperazine hydrochloride (Stelazine Hydrochloride).