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 thiothixene(1)
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: Hyperprolactinemia(3); 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.
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