Off-label, venlafaxine can be used for attention deficit disorder, fibromyalgia, diabetic neuropathy, complex pain syndromes, hot flashes, migraine prevention, post-traumatic stress disorder, obsessive-compulsive disorder, and premenstrual dysphoric disorder.
Venlafaxine may be used independently or as part of combination therapy with other drugs. This activity outlines the indications, mechanism of action, administration methods, significant adverse effects, contraindications, toxicity, and monitoring, of venlafaxine so providers can direct patient therapy where it is indicated as part of the interprofessional team. Objectives: Identify the approved and off-label indications for venlafaxine. Describe the adverse effects associated with venlafaxine, including the FDA black-box warning.
Summarize the relevant drug-drug interactions of venlafaxine. Explain the importance of collaboration and coordination among the interprofessional team and how it can enhance patient care with venlafaxine therapy to improve patient outcomes for patients who have depression and related conditions for which it is indicated. The prevalence of mental disorders in the United States is approximately 30 percent. The global burden of disease statistics shows that four of the ten most important causes of disease worldwide are psychiatric in origin.
The pathophysiology behind psychiatric disorders is the imbalance of the complex neurotransmitter system in the brain. This article will focus on venlafaxine, which belongs to the class of antidepressants called serotonin-norepinephrine reuptake inhibitors SNRIs. Venlafaxine works by increasing serotonin levels, norepinephrine, and dopamine in the brain by blocking transport proteins and stopping their reuptake at the presynaptic terminal. This action leads to more transmitters available at the synapse and ultimately increases the stimulation of postsynaptic receptors.
SNRIs act primarily upon serotonergic and noradrenergic neurons but have little or no effect upon cholinergic or histaminergic receptors.
Venlafaxine is a bicyclic phenylethylamine compound. Venlafaxine is prescribed only for those 18 years and older and should not be used in children under Venlafaxine should be taken with food, and patients should not take it with alcohol as combining alcohol and venlafaxine can lead to increased sedation.
Venlafaxine comes in an oral tablet and an oral capsule. The oral tablets come in immediate-release 25 mg, The immediate-release tablet can be cut or crushed, but the extended-release tablet may not be. Treatment for depression for the immediate release oral table typically starts at 75 mg total per day, given in two or three divided doses.
The typical starting dose of the extended-release oral tablet is 75 mg per day, taken as a single dose in the morning or evening. This dose can be increased by 75 mg every four days until reaching the maximum dose of mg per day. Venlafaxine causes a lower frequency of anticholinergic, sedating, and cardiovascular side effects but a higher incidence of gastrointestinal complaints, sleep impairment, and sexual dysfunction than TCAs. Additionally, venlafaxine may impair sexual function, resulting in diminished libido, impotence, or difficulty achieving orgasm.
Sexual dysfunction frequently results in noncompliance and should be asked about specifically. Sexual dysfunction can sometimes be ameliorated by lowering the dose or instituting drug-free weekends and holidays in appropriate patients. Some patients find withdrawal symptoms uncomfortable. Venlafaxine can cause fatal skin conditions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and erythema multiforme. Venlafaxine can also cause deterioration of glaucoma angle closure and seizures.
Contraindications to venlafaxine include concurrent use of monoamine oxidase inhibitors. Press ESC to cancel. Ben Davis March 11, Can I take Effexor with phentermine? Does Effexor suppress appetite? Is Phentermine How can I prevent insomnia while taking phentermine? Can phentermine cause lack of sleep? Can you take a sleep aid with phentermine?
Can I take Tylenol PM with phentermine? Can phentermine keep you awake? According to the case report, the final hypothesis attributed the psychosis to the dopamine reuptake inhibition of venlafaxine. In addition, a case report 10 published in found erotomania excessive sexual desire was induced by oral venlafaxine in a year-old female. The occurrence of erotomania appeared twice, on separate occasions, when taking venlafaxine. This theory, however, differs from Stahl's theory, 1 as he states venlafaxine is increased only in the prefrontal cortex.
Further investigation into the specific areas of the brain in which dopamine is affected by venlafaxine is warranted. This investigation, however, is beyond the scope of this article. Regarding phentermine, case reports of psychosis have been reported since the late s. First, a year-old woman with a history of bipolar affective disorder suffered from a manic relapse with hallucinations, pressured speech, and argumentative behavior patient A. Next, a year-old woman reported paranoid delusions 1 week after starting phentermine patient B.
In addition, a year-old man developed auditory hallucinations and delusions upon initiating phentermine patient C. Last, a year-old woman developed paranoid delusions and auditory hallucinations after using phentermine for only 6 days patient D.
Three out of 4 cases were resolved upon discontinuation of phentermine; however, because of a lack of information about the year-old, it is undetermined at this time whether symptoms resolved upon discontinuation of phentermine. Returning to the mechanism of action mentioned above, the increase in dopamine likely contributes to the onset of psychosis.
Finally, a case 7 published in the Journal of Clinical Psychopharmacology reported psychosis induced by phentermine administration in a year-old woman with no previous psychiatric history. The woman was taking 30 to 60 mg oral phentermine daily for 4 months prior to this episode.
The patient isolated herself, became extremely agitated, and was convinced she had a transmitter placed in her head. The woman presented to the mental health clinic as these symptoms continued to persist, despite stopping phentermine 10 days prior. She was treated with haloperidol 5 mg by mouth 3 times daily. Approximately 10 days after initiation of the antipsychotic, symptoms resolved, despite the fact that phentermine has an elimination half-life of approximately 20 hours.
This specific article discussed the remission timeline, in which the 10 days of recurrent psychosis after discontinuation of phentermine was consistent with previously published data on phenylpropanolamine, a similar stimulant.
Previous cases have been reported on psychosis induced by venlafaxine alone and by phentermine alone, but not in combination. The proposed mechanisms of each of the medications are consistent with the development of psychotic-like features. When estimating the probability of the adverse drug reaction using the Naranjo Adverse Drug Reaction Probability Scale, the total score is equal to 3, indicating the reaction was possible.
Additional information is needed regarding venlafaxine and the increase in dopamine, specifically in the prefrontal cortex versus various areas of the brain. Last, specific data on topiramate's mechanism of action, specifically in appetite suppression, is lacking, and thus the potential for topiramate's contribution to the development of psychosis cannot definitively be excluded.
National Center for Biotechnology Information , U. Journal List Ment Health Clin v. Ment Health Clin. Published online Mar Author information Copyright and License information Disclaimer. Corresponding author. This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial 3.
Abstract Background: Various publications have noted increases in dopamine, specifically in the mesolimbic region of the brain, to have a direct correlation to psychotic-like symptoms.
Case Report: A year-old Hispanic woman was admitted to the inpatient mental health unit based on reports of delusional thinking and several attempts of self-harm. Background Venlafaxine, a commonly prescribed antidepressant, inhibits the presynaptic reuptake of both serotonin and norepinephrine in the brain. Case Report A year-old Hispanic woman veteran with a past medical history significant for major depressive disorder, posttraumatic stress disorder, anxiety, irritable bowel syndrome, and migraines was admitted to an inpatient psychiatry unit from a walk-in clinic referral.