Effexor XR - Comprehensive Usage Guide: instructions, indications, composition, side effects
Composition
- Active Ingredient: Venlafaxine hydrochloride
- Excipients: May include ethylcellulose, gelatin, hypromellose, iron oxide, magnesium stearate, cellulose, and other inactive ingredients depending on the formulation.
Official Forms
Extended-Release Capsules: Available in various strengths, including 37.5 mg, 75 mg, and 150 mg capsules.
Pharmacological Group
Effexor XR belongs to the pharmacological group of serotonin-norepinephrine reuptake inhibitors (SNRIs) (ATC code: N06AX16).
Pharmacological Properties
- Pharmacodynamics: Venlafaxine exerts its antidepressant effects by inhibiting the reuptake of serotonin and norepinephrine in the synaptic cleft, thereby increasing their neurotransmission in the central nervous system (CNS). It also has weak inhibitory effects on dopamine reuptake.
- Pharmacokinetics: Venlafaxine is well-absorbed after oral administration, with peak plasma concentrations achieved within 2 to 3 hours. It undergoes extensive hepatic metabolism via the cytochrome P450 enzyme system (primarily CYP2D6 and CYP3A4) and is excreted mainly in the urine.
Indications
Effexor XR is indicated for the treatment of:
- Major depressive disorder (MDD)
- Generalized anxiety disorder (GAD)
- Panic disorder (PD)
- Social anxiety disorder (SAD)
Contraindications
Effexor XR is contraindicated in individuals with:
- Hypersensitivity to venlafaxine or any component of the formulation
- Concomitant use of monoamine oxidase inhibitors (MAOIs) or within 14 days of discontinuing MAOI therapy
- Uncontrolled narrow-angle glaucoma
- Concomitant use of thioridazine or linezolid
Interactions
Venlafaxine may interact with other medications, including:
- MAOIs, SSRIs, SNRIs, tricyclic antidepressants, and other serotonergic drugs, increasing the risk of serotonin syndrome
- Drugs that inhibit CYP2D6 enzymes, potentially increasing venlafaxine levels and toxicity
- CNS depressants, alcohol, and drugs that impair cognitive or motor function, potentiating sedation and impairment
Specifics of Use
- Effexor XR capsules should be taken orally once daily with food, preferably in the morning, as directed by a healthcare provider.
- The initial dosage for depression and anxiety disorders is typically 75 mg/day, gradually titrated to a therapeutic dose of 150-225 mg/day based on patient response and tolerability.
- Dosage adjustments should be made cautiously, with close monitoring for adverse effects, especially during initiation or dose changes.
Pregnancy and Breastfeeding
- Effexor XR should be used with caution during pregnancy, especially during the third trimester, and only if the potential benefits outweigh the potential risks to the fetus.
- Venlafaxine is excreted in breast milk, and breastfeeding is not recommended during Effexor XR treatment due to the potential risk to the infant.
Dosage and Administration
- Dosage adjustments may be necessary in patients with hepatic impairment or renal impairment to prevent drug accumulation and minimize the risk of adverse effects.
- Elderly patients may require lower initial doses and slower titration due to age-related changes in drug metabolism.
Overdose
In case of overdose, supportive measures should be initiated, and medical attention should be sought immediately. Symptoms of venlafaxine overdose may include nausea, vomiting, seizures, tachycardia, and coma.
Side Effects
Common side effects of Effexor XR may include:
- Nausea
- Headache
- Dizziness
- Somnolence
- Dry mouth
- Constipation
Storage and Shelf Life
Effexor XR capsules should be stored at controlled room temperature (20-25°C) in a dry place, protected from light and moisture. The expiration date should be checked before use.
These comprehensive instructions provide essential information on the composition, pharmacological properties, indications, contraindications, interactions, administration, side effects, and storage of Effexor XR, aiding healthcare professionals and patients in safe and effective medication use. Always consult a healthcare provider for personalized medical advice.