Effexor

Int J Androl. 2005 Feb;28(1):47-52.
Venlafaxine extended release for the treatment of patients with premature ejaculation: a pilot, single-blind, placebo-controlled, fixed-dose crossover study on short-term administration of an antidepressant drug.
Kilic S, Ergin H, Baydinc YC.
Department of Urology, Turgut Ozal Medical Center, Inonu University School of Medicine, Malatya, Turkey.

In this study, we aimed at evaluating the efficacy and safety of venlafaxine extended release 75 mg, a serotonin and noradrenaline reuptake inhibitor, in the treatment of patients with premature ejaculation. Thirty-one patients with intravaginal ejaculation latency of less than 2 min received venlafaxine XR (75 mg/day) or placebo during a 2-week period for each agent with a washout period of 1 week between agents. Efficacy was assessed for each agent with changes in ejaculation latency measured with a stopwatch and sexual satisfaction scores of patients and partners. Side-effects, pre- and post-treatment levels of biochemical and spermiogram parameters, follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin and total testosterone were recorded for each agent. Statistical analysis was performed on 21 patients. After 2 weeks of treatment with placebo and venlafaxine, ejaculation latency time was significantly increased from 60.1 +/- 39.1 to 126.9 +/- 98.3 sec and to 178.1 +/- 122.8 sec, respectively (p < 0.0001 for each one). However, the difference between the two agents was insignificant (p = 0.144). Venlafaxine and placebo increased sexual satisfaction scores of both patients and partners similarly, no statistically significant difference was found between them in this respect. The incidence of side-effects with venlafaxine was indifferent than that of placebo (p > 0.1) except nausea (p = 0.035). Both agents did not change the blood and spermiogram parameters significantly, except FSH increases. Short-term use of venlafaxine XR 75 mg has only a placebo effect on ejaculation latency and sexual satisfaction scores, therefore, is not appropriate for the patients with premature ejaculation. Further dose-time studies are required to draw final conclusions on the inefficacy of this drug in premature ejaculation.

GENERIC NAME: venlafaxine
BRAND NAME: Effexor, Effexor XR

DRUG CLASS AND MECHANISM: Venlafaxine is in a new class of anti-depressant medications that affects chemical messengers within the brain. These chemical messengers are called neurotransmitters, and some examples are serotonin, dopamine, and norepinephrine. Neurotransmitters are manufactured by nerve cells and are released by the cells. The neurotransmitters travel to nearby nerve cells and cause the cells to become more or less active. Many experts believe that an imbalance in these neurotransmitters is the cause of depression and also may play a role in anxiety. Venlafaxine is believed to work by inhibiting the release or affecting the action of these neurotransmitters.

PREPARATIONS: Effexor is available in tablets of 25, 37.5, 50, 75, and 100 mg. Effexor XR is available in capsules of 37.5, 75, and 150 mg.

STORAGE: Store in a dry place at 20-25°C (68-77°F).

PRESCRIBED FOR: Venlafaxine is prescribed for the treatment of depression, depression with associated symptoms of anxiety, generalized anxiety disorder, and social anxiety disorder.

DOSING: Venlafaxine should be taken with food at doses specifically directed by a physician. Individual doses vary greatly among individuals. The anti-depressant effects are not maximal for 1-2 weeks. If discontinued, the dose of venlafaxine should gradually be reduced under the direction of a physician. For patients with difficulty swallowing tablets or capsules, capsules of Effexor XR can be opened and the contents sprinkled on a spoonful of applesauce.

DRUG INTERACTIONS: Life-threatening interactions can occur in combination with MAO inhibitors such as Nardil and Parnate. MAO inhibitors and venlafaxine should not be taken together, and a waiting period of 14 days between taking these two classes of medications is strongly advised.

Most medications affecting the brain such as venlafaxine have the potential to slow reflexes or impair judgment. Therefore, caution is advised especially early in the course of treatment.

Safety has not been established in children below the age of 18 years.

PREGNANCY: The effects of venlafaxine on the fetus are unknown.

NURSING MOTHERS: It is not known if venlafaxine is secreted in milk and, therefore, if it may have an effect on nursing infants.

SIDE EFFECTS: Venlafaxine, like most anti-depressants, can cause nausea, headaches, anxiety, insomnia, drowsiness, and loss of appetite. Increased blood pressure can occur, and blood pressure should be monitored. Seizures have been reported.

"If anti-depressants are discontinued abruptly, symptoms may occur such as dizziness, headache, nausea, changes in mood, or changes in the sense of smell, taste, etc. (Such symptoms even may occur when even a few doses of anti-depressant are missed.) Therefore, it is recommended that the dose of anti-depressant be reduced gradually when therapy is discontinued."

RECOMMENDED DOSAGE:
EFFEXOR
The usual starting dose is 75 milligrams a day, divided into 2 or 3 smaller doses, and taken with food. If needed, your doctor may gradually increase your daily dose in steps of no more than 75 milligrams at a time up to a maximum of 375 milligrams per day. If you have kidney or liver disease or are taking other medications, your doctor will adjust your dosage accordingly.

EFFEXOR XR
For both depression and anxiety the usual starting dose is 75 milligrams once daily, although some people begin with a dose of 37.5 milligrams for the first 4 to 7 days. Your doctor may gradually increase the dose, in steps of no more than 75 milligrams, up to a maximum of 225 milligrams daily. As with regular Effexor, the doctor will make adjustments in your dosage if you have kidney or liver disease.

SPECIAL WARNINGS ABOUT THIS MEDICATION: Your doctor will prescribe Effexor with caution if you have high blood pressure, heart, liver, or kidney disease or a history of seizures or mania (extreme agitation or excitability). You should discuss all of your medical problems with your doctor before taking Effexor. Effexor sometimes causes an increase in blood pressure. If this happens, your doctor may need to reduce your dose or discontinue the drug. Effexor also tends to increase the heart rate, especially at higher doses. Use Effexor with caution if you've recently had a heart attack, suffer from heart failure, or have an overactive thyroid gland. Antidepressants such as Effexor may cause fluid retention, especially if you are an older adult. Effexor may cause you to feel drowsy or less alert and may affect your judgment. Therefore, avoid driving or operating dangerous machinery or participating in any hazardous activity that requires full mental alertness until you know how this drug affects you. Your doctor will check you regularly if you have glaucoma (high pressure in the eye), or you are at risk of developing it. If you have ever been addicted to drugs, tell your doctor before you start taking Effexor. If you develop a skin rash or hives while taking Effexor, notify your doctor. Effexor may also cause bleeding or bruising of the skin. Do not stop taking the drug without consulting your doctor. If you stop suddenly, you may have withdrawal symptoms, even though this drug does not seem to be habit-forming. Your doctor will have you taper off gradually. The safety and effectiveness of Effexor have not been established in children under 18 years of age.

Caution! Before starting to take this medicine, it is vital that you should consult your doctor! Do not use it on your own initiative, without medical advice.