Venlafaxine (Effexor%26reg;) is a new antidepressant with a chemical structure that does not resemble those of any currently used antidepressants. Effexor XR%26reg; (Venlafaxine HCL) is a medication available to treat depression and generalized anxiety disorder .It is important to know that Effexor%26reg; is not a tricyclic antidepressant or an MAO inhibitor. The fact is that everyone responds to medications differently. Effexor XR%26reg; will work well for some people, and not so well for others. Research has shown that Venlafaxine is the most effective among six commonly prescribed antidepressants.
What makes it so different from other antidepressants?
Effexor seems to have the relative freedom from side-effects associated with the:
%26bull; SSRIs such as fluoxetine (Prozac%26reg;), sertraline (Zoloft%26reg;), paroxetine (Paxil%26reg;), and fluvoxamine (Luvox%26reg;) and
%26bull; The impact on both serotonin and norepinephrine associated with the tricyclic antidepressants [amitriptyline (Elavi%26reg;l), imipramine (Tofranil%26reg;).
Effexor is different than other antidepressants because it contains the drug known as Venlafaxine which should be prescribed only to people suffering from major depression or extreme anxiety. This drug has been successful in treating people with depression that have not responded to other antidepressants.
Metabolism and mechanism of action
This drug belongs to a class of antidepressants called serotonin-norepinephrine reuptake inhibitors (SNRI). As Venlafaxine and its active metabolite have relatively short half-lives, 4 hours and 11 hours respectively, Effexor should be administered in divided does, two or three times a day. Venlafaxine is well absorbed, with peak plasma concentrations occurring approximately 2 hours after dosing. Structurally different from any other antidepressant, it affects two neurotransmitters involved in depression, serotonin and norepinephrine. Several researches have proven that this medication works by correcting the balance of two brain chemicals serotonin and norepinephrine.
Why are these substances so important? It is proven that these two chemicals help control moods, concentration, impulses, appetites, irritability and emotions.
That%26rsquo;s why imbalances of these substances create the cycle of depression and the nervousness and irritability associated with anxiety disorders.
It is proven that at low and medium dosages, Effexor diminishes serotonin reuptake alone and at higher dosages, it inhibits the reuptake of norepinephrine as well as serotonin and dopamine.
Like most other medications used for depression, Effexor may take several weeks before it is fully effective and that%26rsquo;s why it is important to give the medication sufficient time before judging whether it works for a given person.
Before using this medicine
Before you start taking Effexors, there are several things you should know about it and it%26rsquo;s side effects:
%26bull; Allergies
The doctor needs to be informed about any allergic reaction to Venlafaxine or about allergy to any other substances, such as foods, preservatives, or dyes.
%26bull; Pregnancy
Some research conducted on animals showed that Effexor may have serious side effects on pregnancy. You need to inform your doctor that you%26rsquo;re pregnant before he prescribes you this medicine.
%26bull; Breast-feeding
This medicine passes into breast milk and may cause unwanted effects.
%26bull; Children
Venlafaxine must be used with caution in children with depression because several studies have shown occurrences of suicidal tendencies in children who participated in clinical trials for this medicine.
%26bull; Other medicines
You should consult the physician if you plan to start taking Effexor while already on:
%26bull; Buspirone
%26bull; Bromocriptine
%26bull; Certain tricyclic antidepressants
%26bull; Dextromethorphan
%26bull; Levodopa
%26bull; Lithium
%26bull; Meperidine
%26bull; Nefazodone
%26bull; Pentazocine
%26bull; Selective serotonin reuptake inhibitors
%26bull; Street drugs (LSD, MDMA [e.g., ecstasy], marijuana)
%26bull; Sumatriptan
%26bull; Tramadol
%26bull; Trazodone
%26bull; Tryptophan
%26bull; Clozapine
%26bull; Monoamine oxidase (MAO) inhibitor activity
%26bull; Warfarin
Effexor indications
%26bull; Depression and generalized anxiety disorder
Effexor XR is recognized as an effective first-time medication for patients who suffer from depression or who have generalized anxiety disorder. It doesn%26rsquo;t matter whether they are hospitalized or treated on an outpatient basis.
%26bull; Longstanding depressive illness
It can also be useful for patients who have had longstanding depressive illness and have not responded adequately to previous treatments.
%26bull; Unsuccessful previous treatments
A great deal of so-called refractory patients or those who have not had positive results from past treatment have had success with Effexor XR.
Recommended dosage
%26bull; Effexor%26reg;
The usual starting dose is 75 milligrams a day, divided into 2 or 3 smaller doses. It should always be taken with food. If needed, the doctor may gradually increase the daily dose in steps of no more than 75 milligrams at a time up to a maximum of 375 milligrams per day.
%26bull; Effexor XR%26reg;
For both depression and anxiety the usual starting dose is 75 milligrams once a day, 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.
Possible side effects of Effexor
A warning is being issued with Effexor and with other SSRI and SSRN anti-depressants advising of risk of suicidality. Family members should be advised of this potentially fatal side effect so they may bring the patient to a hospital emergency for surveillance and protection.
Common side effects include:
%26bull; Nausea
%26bull; Dizziness
%26bull; Sleepiness
%26bull; Insomnia
%26bull; Vertigo
%26bull; Dry mouth
%26bull; Sexual dysfunction
%26bull; Sweating
%26bull; Vivid dreams
%26bull; Increased blood pressure
%26bull; Electric shock like sensations
Less Common side-effects include:
%26bull; Panic Attacks
%26bull; Drowsiness
%26bull; Depressed feelings
%26bull; Cardiac arrhythmia
%26bull; Increased serum cholesterol
%26bull; Gas or stomach pain
%26bull; Abnormal vision
%26bull; Nervousness, agitation or increased anxiety
%26bull; Suicidal thoughts suicidal ideation
%26bull; Confusion
%26bull; Neuroleptic malignant syndrome
%26bull; Loss of appetite
%26bull; Constipation
%26bull; Tremor
%26bull; Tardive dyskinesia
%26bull; Difficulty swallowing
%26bull; Lack of sexual desire
%26bull; Raised blood pressure
%26bull; Allergic skin reactions
%26bull; External bleeding
%26bull; Serious bone marrow damage
%26bull; Hepatitis
%26bull; Pancreatitis
%26bull; Seizure
Effexor and other medications
Effexor XR%26reg; does not interact significantly with many other medications, including Lithium%26reg;, Valium%26reg; (diazepam), and Tagamet%26reg; (cimetidine, an anti-ulcer medication). While taking Tagamet %26reg; for high blood pressure or liver disease the patient should be cautious in taking Effexor XR%26reg; because the interaction may be more pronounced when these disorders are present. Effexor XR%26reg; definitely should not be taken at the same time as the MAOIs (Parnate%26reg; or Nardil%26reg;). Interactions with these compounds could be lethal.
Physical and Psychological Dependence
Although no researches have been conducted on humans, several in vitro studies revealed that Effexor has virtually no affinity for opiate, benzodiazepine, phencyclidine (PCP), or N-methyl-D-aspartic acid (NMDA) receptors.
There was no indication of drug-seeking behavior in the clinical trials. However, it is not possible to predict on the basis of experience the extent to which a CNS active drug will be misused, diverted, or abused once marketed.
Withdrawal symptoms
Effexor%26reg; may cause potentially serious withdrawal symptoms upon sudden discontinuation. These withdrawal symptoms have a tendency to be significantly stronger than the withdrawal effects of other antidepressants including the tricyclic antidepressants.
Discontinuation effects may include:
%26bull; irritability,
%26bull; hostility,
%26bull; headache,
%26bull; nausea,
%26bull; fatigue,
%26bull; dysphoria
%26bull; brain shivers
Rarer withdrawal symptoms include:
%26bull; shaking legs,
%26bull; tremor,
%26bull; vertigo,
%26bull; Abdominal or stomach pain;
%26bull; agitation;
%26bull; black, tarry stools;
%26bull; bleeding gums;
%26bull; blistering,
%26bull; peeling,
%26bull; loosening of skin;
%26bull; bloating of abdomen;
%26bull; blood in eye;
%26bull; bloody urine;
%26bull; confusion
%26bull; dizziness
%26bull; paresthesia
%26bull; impaired concentration,
%26bull; bizarre dreams,
%26bull; agitation
%26bull; suicidal thoughts
Effexor and suicide
The possibility of a suicide attempt in seriously depressed patients is inherent to the illness and may persist until significant remission occurs.
Close supervision of high-risk patients should accompany initial drug therapy, and consideration should be given to the need for hospitalization. In order to reduce the risk of overdose, prescriptions for Effexor should be written for the smallest quantity of tablets consistent with good patient management.
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