Drowsiness, dizziness, amenorrhea, blurred vision, skin
reactions and hypotension may occur.
Cholestatic jaundice has occurred. If fever with
grippe-like symptoms occurs, appropriate liver studies should be conducted. If
tests indicate an abnormality, stop treatment. There have been a few observations
of fatty changes in the livers of patients who have died while receiving the
drug. No causal relationship has been established.
Leukopenia and agranulocytosis have occurred. Warn
patients to report the sudden appearance of sore throat or other signs of
infection. If white blood cell and differential counts indicate leukocyte depression,
stop treatment and start antibiotic and other suitable therapy.
Neuromuscular (Extrapyramidal) Reactions
These symptoms are seen in a significant number of
hospitalized mental patients. They may be characterized by motor restlessness,
be of the dystonic type, or they may resemble parkinsonism.
Depending on the severity of symptoms, dosage should be
reduced or discontinued. If therapy is reinstituted, it should be at a lower
dosage. Should these symptoms occur in children or pregnant patients, the drug
should be stopped and not reinstituted. In most cases barbiturates by suitable
route of administration will suffice. (Or, injectable diphenhydramine may be
useful.) In more severe cases, the administration of an anti-parkinsonism
agent, except levodopa (see PDR), usually produces rapid reversal of
symptoms. Suitable supportive measures such as maintaining a clear airway and
adequate hydration should be employed.
Symptoms may include agitation or jitteriness and
sometimes insomnia. These symptoms often disappear spontaneously. At times
these symptoms may be similar to the original neurotic or psychotic symptoms. Dosage
should not be increased until these side effects have subsided.
If these symptoms become too troublesome, they can
usually be controlled by a reduction of dosage or change of drug. Treatment
with anti-parkinsonian agents, benzodiazepines or propranolol may be helpful.
Symptoms of dystonia, prolonged abnormal contractions of
muscle groups, may occur in susceptible individuals during the first few days
of treatment. Dystonic symptoms include: spasm of the neck muscles, sometimes
progressing to tightness of the throat, swallowing difficulty, difficulty
breathing, and/or protrusion of the tongue. While these symptoms can occur at
low doses, they occur more frequently and with greater severity with high
potency and at higher doses of first generation antipsychotic drugs. An
elevated risk of acute dystonia is observed in males and younger age groups.
Symptoms may include: mask-like facies; drooling;
tremors; pillrolling motion; cogwheel rigidity; and shuffling gait. Reassurance
and sedation are important. In most cases these symptoms are readily controlled
when an anti-parkinsonism agent is administered concomitantly.
Anti-parkinsonism agents should be used only when required. Generally, therapy
of a few weeks to 2 or 3 months will suffice. After this time patients should
be evaluated to determine their need for continued treatment. (Note: Levodopa
has not been found effective in pseudo-parkinsonism.) Occasionally it is
necessary to lower the dosage of prochlorperazine or to discontinue the drug.
As with all antipsychotic agents, tardive dyskinesia may
appear in some patients on long-term therapy or may appear after drug therapy
has been discontinued. The syndrome can also develop, although much less
frequently, after relatively brief treatment periods at low doses. This
syndrome appears in all age groups. Although its prevalence appears to be
highest among elderly patients, especially elderly women, it is impossible to
rely upon prevalence estimates to predict at the inception of neuroleptic treatment
which patients are likely to develop the syndrome. The symptoms are persistent
and in some patients appear to be irreversible. The syndrome is characterized
by rhythmical involuntary movements of the tongue, face, mouth or jaw (e.g.,
protrusion of tongue, puffing of cheeks, puckering of mouth, chewing
movements). Sometimes these may be accompanied by involuntary movements of
extremities. In rare instances, these involuntary movements of the extremities
are the only manifestations of tardive dyskinesia. A variant of tardive
dyskinesia, tardive dystonia, has also been described.
There is no known effective treatment for tardive
dyskinesia; anti-parkinsonism agents do not alleviate the symptoms of this
syndrome. It is suggested that all antipsychotic agents be discontinued if
these symptoms appear.
Should it be necessary to reinstitute treatment, or
increase the dosage of the agent, or switch to a different antipsychotic agent,
the syndrome may be masked.
It has been reported that fine vermicular movements of
the tongue may be an early sign of the syndrome and if the medication is
stopped at that time the syndrome may not develop.
Adverse Reactions Reported With Prochlorperazine Or Other
Adverse reactions with different phenothiazines vary in
type, frequency and mechanism of occurrence, i.e., some are dose-related, while
others involve individual patient sensitivity. Some adverse reactions may be
more likely to occur, or occur with greater intensity, in patients with special
medical problems, e.g., patients with mitral insufficiency or pheochromocytoma
have experienced severe hypotension following recommended doses of certain
Not all of the following adverse reactions have been
observed with every phenothiazine derivative, but they have been reported with
1 or more and should be borne in mind when drugs of this class are administered:
extrapyramidal symptoms (opisthotonos, oculogyric crisis, hyperreflexia,
dystonia, akathisia, dyskinesia, parkinsonism) some of which have lasted months
and even years- particularly in elderly patients with previous brain damage;
grand mal and petit mal convulsions, particularly in patients with EEG
abnormalities or history of such disorders; altered cerebrospinal fluid
proteins; cerebral edema; intensification and prolongation of the action of
central nervous system depressants (opiates, analgesics, antihistamines,
barbiturates, alcohol), atropine, heat, organophosphorus insecticides; autonomic
reactions (dryness of the mouth, nasal congestion, headache, nausea,
constipation, obstipation, adynamic ileus, ejaculatory disorders/impotence,
priapism, atonic colon, urinary retention, miosis and mydriasis); reactivation
of psychotic processes, catatonic-like states; hypotension (sometimes fatal);
cardiac arrest; blood dyscrasias (pancytopenia, thrombocytopenic purpura, leukopenia,
agranulocytosis, eosinophilia, hemolytic anemia, aplastic anemia); liver damage
(jaundice, biliary stasis); endocrine disturbances (hyperglycemia,
hypoglycemia, glycosuria, lactation, galactorrhea, gynecomastia, menstrual
irregularities, false-positive pregnancy tests); skin disorders (photosensitivity,
itching, erythema, urticaria, eczema up to exfoliative dermatitis); other
allergic reactions (asthma, laryngeal edema, angioneurotic edema, anaphylactoid
reactions); peripheral edema; reversed epinephrine effect; hyperpyrexia; mild
fever after large I.M. doses; increased appetite; increased weight; a systemic
lupus erythematosus-like syndrome; pigmentary retinopathy; with prolonged
administration of substantial doses, skin pigmentation, epithelial keratopathy,
and lenticular and corneal deposits.
EKG changes-particularly nonspecific, usually reversible
Q and T wave distortions-have been observed in some patients receiving
Although phenothiazines cause neither psychic nor
physical dependence, sudden discontinuance in long-term psychiatric patients
may cause temporary symptoms, e.g., nausea and vomiting, dizziness, tremulousness.
Note: There have been occasional reports of sudden
death in patients receiving phenothiazines. In some cases, the cause appeared
to be cardiac arrest or asphyxia due to failure of the cough reflex.
No information provided.