Product Code Database
Perphenazine is a typical antipsychotic drug. Chemically, it is classified as a piperazinyl phenothiazine. Originally marketed in the United States as Trilafon, it has been in clinical use for decades.
Perphenazine is roughly ten times as potent as chlorpromazine at the dopamine-2 (D2) receptor; thus perphenazine is considered a medium-potency antipsychotic.
Perphenazine has been used in low doses as a 'normal' or 'minor' tranquilizer in patients with a known history of addiction to drugs or Alcoholism, a practice which is now strongly discouraged.
Perphenazine has sedating and anxiolytic properties, making the drug useful for the treatment of agitated psychotic patients.
A valuable off-label indication is the short-time treatment of hyperemesis gravidarum, in which pregnant women experience violent nausea and vomiting. This problem can become severe enough to endanger the pregnancy. As perphenazine has not been shown to be teratogenic and works very well, it is sometimes given orally in the smallest possible dose.
| + Perphenazine compared with any antipsychotic drug for schizophrenia |
| Although perphenazine has been used in randomized trials for more than 50 years, incomplete reporting and the variety of comparators used make it impossible to draw clear conclusions. All data for the main outcomes were of very low quality evidence. At best it can be said that perphenazine showed similar effects—including adverse events—as several of the other antipsychotic drugs. |
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When used for its strong antiemetic or antivertignosic effects in cases with associated brain injuries, it may obscure the clinical course and interferes with the diagnosis. High doses of perphenazine can cause temporary dyskinesia. As with other typical antipsychotics, permanent or lasting tardive dyskinesia is a risk.
There is tentative evidence that discontinuation of antipsychotics can result in psychosis. It may also result in reoccurrence of the condition that is being treated.
Rarely tardive dyskinesia can occur when the medication is stopped.
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Mechanisms
Perphenazine is a typical antipsychotic medication of midrange or moderate potency (the 15-fold of a chlorpromazine dosage, also a typical antipsychotic medication). Compared with the high potent typical antipsychotic drug haloperidol (50-fold), it despite is considered by some to have similar extrapyramidal side-effects. This is probably because it has similar affinity values at the D2/3 receptors (0.7, 0.3). Compared to other substance types of antipsychotics of the phenothiazine family, perphenazine does have comparable greater behavioral effects in respective to its antipsychotic potency (compared to other phenothiazines), so it could be considered to be favorable or efficient as add-on if the adherence of the patient to the daily clinical life is somehow too missing or not really sufficient.
There exists a distingtion to separate the type an antipsychotic is blocking into pure (silent) antagonists and inverse agonists (but with both, antagonists and inverse agonists inducing the same therapeutic effect, in case of antipsychotics) where it seems to tend out that inverse agonists at least occurs very often at exactly this from a specific neuroleptic's bindingsite which is weightened the most potent and therapeutic effect initiating bindingsite of each neuroleptic's individuall affinityprofile (e.g. 5HT2A in Clo- and Olanzapine, H1 in Olanzapine, D2 in Haloperidole). Perphenazine here makes an exception being a normal antagonist in its most important bindingsite (D2).
The 'Perphenazine injectable USP' solution is intended for deep intramuscular (i.m.) injection, for patients who are not willing to take oral medication or if the patient is unable to swallow. Due to a better bioavailability of the injection, two-thirds of the original oral dose is sufficient. The incidence of hypotension, sedation and extrapyramidal side-effects may be higher compared to oral treatment. The i.m.-injections are appropriate for a few days, but oral treatment should start as soon as possible.
In many countries, depot forms of perphenazine exist (as perphenazine enanthate and perphenazine decanoate). One injection works for 1 to 4 weeks depending on the dose of the depot-injection. Depot-forms of perphenazine should not be used during the initial phase of treatment as the rare neuroleptic malignant syndrome may become more severe and uncontrollable with this form. Extrapyramidal side-effects may be somewhat reduced due to constant plasma-levels during depot-therapy. Also, patient compliance is sure, as many patients do not take their oral medication, particularly if feeling better once improvement in psychosis is achieved.
Perphenazine intensifies the central depressive action of drugs with such activity (tranquilizers, hypnotics, narcotics, antihistaminics, OTC- etc.). A dose reduction of perphenazine or the other drug may be necessary.
In general, all may lead to seizures in combination with the opioid tramadol (Ultram).
Perphenazine may increase the insulin needs of diabetic patients. Monitor blood glucose levels of insulin-dependent patients regularly during long-term treatment.
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