SIDE EFFECTS
NOTE: Not all of the following adverse reactions
have been reported with Navane. However, since Navane has certain chemical and
pharmacologic similarities to the phenothiazines, all of the known side effects
and toxicity associated with phenothiazine therapy should be borne in mind when
Navane is used.
Cardiovascular Effects
Tachycardia, hypotension, lightheadedness, and syncope.
In the event hypotension occurs, epinephrine should not be used as a pressor
agent since a paradoxical further lowering of blood pressure may result.
Nonspecific EKG changes have been observed in some patients receiving Navane.
These changes are usually reversible and frequently disappear on continued
Navane therapy. The incidence of these changes is lower than that observed with
some phenothiazines. The clinical significance of these changes is not known.
CNS Effects
Drowsiness, usually mild, may occur although it usually
subsides with continuation of Navane therapy. The incidence of sedation appears
similar to that of the piperazine group of phenothiazines but less than that of
certain aliphatic phenothiazines. Restlessness, agitation and insomnia have
been noted with Navane. Seizures and paradoxical exacerbation of psychotic
symptoms have occurred with Navane infrequently.
Hyperreflexia has been reported in infants delivered from
mothers having received structurally related drugs.
In addition, phenothiazine derivatives have been
associated with cerebral edema and cerebrospinal fluid abnormalities.
Extrapyramidal Symptoms
Extrapyramidal symptoms, such as pseudoparkinsonism,
akathisia and dystonia have been reported (see Dystonia, Class effect).
Management of these extra-pyramidal symptoms depends upon the type and
severity. Rapid relief of acute symptoms may require the use of an injectable
antiparkinson agent. More slowly emerging symptoms may be managed by reducing
the dosage of Navane and/or administering an oral antiparkinson agent.
Dystonia
Class Effect
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.
Persistent Tardive Dyskinesia
As with all antipsychotic agents, tardive dyskinesia may
appear in some patients on long-term therapy with thiothixene1 or
may occur after drug therapy has been discontinued. 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.
Since early detection of tardive dyskinesia is important,
patients should be monitored on an ongoing basis. It has been reported that
fine vermicular movement of the tongue may be an early sign of the syndrome. If
this or any other presentation of the syndrome is observed, the clinician
should consider possible discontinuation of antipsychotic medication. (See WARNINGS
section.)
Hepatic Effects
Elevations of serum transaminase and alkaline
phosphatase, usually transient, have been infrequently observed in some
patients. No clinically confirmed cases of jaundice attributable to Navane
(thiothixene) have been reported.
Hematologic Effects
As is true with certain other psychotropic drugs,
leukopenia and leucocytosis, which are usually transient, can occur
occasionally with Navane. Other antipsychotic drugs have been associated with
agranulocytosis, eosinophilia, hemolytic anemia, thrombocytopenia and
pancytopenia.
Allergic Reactions
Rash, pruritus, urticaria, photosensitivity and rare
cases of anaphylaxis have been reported with Navane. Undue exposure to sunlight
should be avoided. Although not experienced with Navane, exfoliative dermatitis
and contact dermatitis (in nursing personnel) have been reported with certain
phenothiazines.
Endocrine/Reproductive
Hyperprolactinemia3; lactation, menstrual
irregularities, moderate breast enlargement and amenorrhea have occurred in a
small percentage of females receiving Navane. If persistent, this may
necessitate a reduction in dosage or the discontinuation of therapy.
Phenothiazines have been associated with false positive pregnancy tests,
gynecomastia, hypoglycemia, hyperglycemia and glycosuria.
Autonomic Effects
Dry mouth, blurred vision, nasal congestion,
constipation, increased sweating, increased salivation and impotence have occurred
infrequently with Navane therapy. Phenothiazines have been associated with
miosis, mydriasis, and adynamic ileus.
Other Adverse Reactions
Hyperpyrexia, anorexia, nausea, vomiting, diarrhea,
increase in appetite and weight, weakness or fatigue, polydipsia, and
peripheral edema.
Although not reported with Navane, evidence indicates
there is a relationship between phenothiazine therapy and the occurrence of a
systemic lupus erythematosus-like syndrome.
Neuroleptic Malignant Syndrome (NMS)
Please refer to the text regarding NMS in the WARNINGS section.
NOTE: Sudden deaths have occasionally been reported in
patients who have received certain phenothiazine derivatives. In some cases the
cause of death was apparently cardiac arrest or asphyxia due to failure of the
cough reflex. In others, the cause could not be determined nor could it be
established that death was due to phenothiazine administration.