Venlax prolonged-release capsules (venlafaxine) 37.5 mg and 75 mg – depression and anxiety disorders

Venlax is an antidepressant containing the active substance venlafaxine (as venlafaxine hydrochloride) and belongs to the group of serotonin and noradrenaline reuptake inhibitors (SNRIs). In Serbia it is authorised as prolonged-release hard capsules of 37.5 mg and 75 mg; the manufacturer and marketing authorisation holder is Galenika a.d. Belgrade.

Venlax is used to treat adults with depression and with anxiety disorders: generalised anxiety disorder, social anxiety disorder and panic disorder. Improvement is usually expected only after two weeks or later, and treatment lasts several months as decided by the doctor.

What is Venlax (venlafaxine) used for and how should it be taken?

Key facts about the medicine

What is Venlax used for?

According to the official leaflet, Venlax is used to treat adults with:

• depression;
• generalised anxiety disorder (persistent, marked worry and fear);
• social anxiety disorder (fear and avoidance of social situations and public appearances);
• panic disorder (panic attacks).

If depression and anxiety are not treated, the condition may worsen and become harder to treat.

How is it used and dosed?

The medicine is taken once daily with food at about the same time (morning or evening). The capsule is swallowed whole with liquid – it must not be opened, crushed, chewed or dissolved.

In depression the antidepressant is continued for at least 6 months after remission. This is the general dosing from the leaflet and summary of product characteristics; dose and duration are set by the doctor.

Special patient groups

• Liver impairment: in mild to moderate impairment a 50% dose reduction is considered, in severe impairment more than 50%, weighing benefits and risks.
• Kidney impairment: no adjustment at GFR 30–70 mL/min (caution); at GFR < 30 mL/min and on haemodialysis the dose is reduced by 50%.
• Elderly: no adjustment on the basis of age alone, but caution and the lowest effective dose are needed.
• Children and adolescents under 18: not recommended; increased risk of suicidal thoughts and hostile behaviour.
• Diabetes: the medicine may affect blood sugar, so diabetes treatment may need adjustment.

Contraindications – when the medicine must not be used

Do not take Venlax:

• if you are allergic to venlafaxine or any of the excipients;
• if you are taking or have taken an irreversible monoamine oxidase inhibitor (MAOI) in the previous 14 days – after stopping Venlax wait at least 7 days before starting an MAOI.

Precautions and warnings

• Glaucoma or other eye problems (possible pupil dilation).
• High blood pressure now or in the past – blood pressure should be checked before starting, periodically during treatment and with each dose increase.
• Heart problems or heart rhythm disorders.
• History of seizures, low blood sodium.
• Bleeding tendency or use of medicines that increase bleeding (e.g. warfarin).
• Mania or bipolar disorder (personal or family), tendency to aggressive behaviour.
• In the first weeks restlessness and inability to sit or stand still (akathisia) may occur.
• Dry mouth in about 10% of patients – increased risk of tooth decay, extra oral hygiene needed.
• Sexual dysfunction; in some people symptoms continue after stopping treatment.

Interactions with other medicines, alcohol and food

• Contraindicated: irreversible MAO inhibitors.
• Serotonin syndrome possible with: triptans, other antidepressants (SNRIs, SSRIs, tricyclics), lithium, amphetamines, linezolid, moclobemide, sibutramine, tramadol, fentanyl, tapentadol, pethidine, pentazocine, dextromethorphan, methadone, methylene blue, St John’s wort, tryptophan products and antipsychotics.
• Medicines affecting heart rhythm: antiarrhythmics (quinidine, amiodarone, sotalol, dofetilide), thioridazine, erythromycin, moxifloxacin, antihistamines.
• Caution with ketoconazole, haloperidol, risperidone and metoprolol.
• Alcohol: do not drink during treatment. Take the medicine with food.
• Do not start or stop any medicine, herbal or natural product without consulting your doctor.

Pregnancy and breastfeeding

Venlax is used in pregnancy only if the doctor considers the benefit greater than the risk to the baby. Use of similar medicines in late pregnancy increases the risk of persistent pulmonary hypertension of the newborn (rapid breathing, bluish colour in the first 24 hours), and feeding difficulties may occur; tell your gynaecologist and midwife that you take the medicine.

Venlafaxine passes into breast milk and there is a risk to the baby; the doctor decides whether to stop breastfeeding or treatment.

Driving and using machines

Do not drive or use machines until you know how Venlax affects you (dizziness, drowsiness and blurred vision are possible).

Possible side effects

• Very common (more than 1 in 10): dizziness, headache, drowsiness, insomnia, nausea, dry mouth, constipation, sweating (including night sweats).
• Common (up to 1 in 10): loss of appetite, confusion, feeling detached, orgasm disorders and reduced sexual desire, nervousness, abnormal dreams, tremor, akathisia, tingling, altered taste, visual disturbances and dilated pupils, ringing in the ears, fast heartbeat and palpitations, raised blood pressure, flushing, yawning, vomiting, diarrhoea, rash, itching, urination problems, menstrual disorders, erectile dysfunction, weakness, weight change, raised cholesterol.
• Uncommon (up to 1 in 100): mania, hallucinations, agitation, teeth grinding, fainting, drop in blood pressure on standing, gastrointestinal bleeding, sensitivity to sunlight, bruising, hair loss, angioedema, abnormal liver enzymes.
• Rare (up to 1 in 1,000): seizures, delirium, SIADH and low sodium, acute glaucoma, heart rhythm disorders, hepatitis, serotonin syndrome, anaphylaxis, severe skin reactions, rhabdomyolysis.
• Not known: thoughts of self-harm and suicide, aggression, vertigo, stress cardiomyopathy.

Report suspected side effects to your doctor, pharmacist or ALIMS.

Overdose, missed dose and stopping treatment

• Overdose: fast heartbeat, altered consciousness (from drowsiness to coma), blurred vision, seizures and vomiting. Contact a doctor or healthcare facility immediately.
• Missed dose: take it as soon as you remember; if it is already time for the next dose, skip the missed one. Do not take more than the prescribed daily dose.
• Stopping treatment: do not stop the medicine yourself, even if you feel better. Abrupt stopping or too rapid reduction may cause tiredness, dizziness, headache, insomnia and nightmares, nausea, diarrhoea, irritability, agitation, ringing in the ears, tingling or electric shock-like sensations, sweating, seizures and flu-like symptoms. The dose is reduced gradually over at least 1–2 weeks.

Related information

• Anxiety and anxiety disorders
• How is anxiety treated and what are the preventive measures?

Composition, packaging and manufacturer

• Active substance: venlafaxine (as venlafaxine hydrochloride) 37.5 mg or 75 mg per capsule.
• Tablet core inside the capsule: hypromellose, Eudragit RS 100, sodium lauryl sulfate, magnesium stearate; film coating: Eudragit E 12.5.
• Capsule: titanium dioxide (E171), gelatin; the 75 mg capsule also contains red iron oxide (E172).
• Pack: PVC/PE/PVDC/Al blister with 10 capsules; carton with 30 capsules (3 × 10).
• Marketing authorisation holder and manufacturer: GALENIKA AD BEOGRAD, Batajnički drum b.b., Belgrade.

Storage

• Store in the original package.
• Keep out of the sight and reach of children; do not use after the expiry date.
• Return unused medicine to a pharmacy that collects unused medicines.

Frequently asked questions

When does Venlax start to work?

According to the leaflet, improvement is expected only after two weeks and sometimes later. In the first weeks it is important to take the medicine regularly and to contact the doctor if mood worsens or thoughts of self-harm appear.

Can Venlax be stopped suddenly?

No. Abrupt stopping or too rapid dose reduction can cause withdrawal symptoms (dizziness, nausea, insomnia, agitation, tingling, “electric shock” sensations). The doctor plans a gradual reduction, usually over at least 1–2 weeks.

Can the Venlax capsule be opened?

No. The prolonged-release capsule is swallowed whole with liquid and must not be opened, crushed, chewed or dissolved, as this would disrupt the gradual release of the medicine.

Does Venlax affect blood pressure?

It can. Raised blood pressure is a common side effect, so blood pressure is checked before treatment, periodically during treatment and at each dose increase. Caution is needed in people with heart disease.

Is Venlax 75 mg the same as two 37.5 mg capsules?

The 75 mg capsule contains two 37.5 mg tablets inside one capsule. Both strengths contain the same medicine; your doctor decides which strength and how many capsules you take.

Sources

• ALIMS – Patient leaflet Venlax®, 37.5 mg and 75 mg prolonged-release hard capsules (August 2020, Serbian)
• ALIMS – Summary of product characteristics Venlax®, 37.5 mg and 75 mg (Serbian)

Sources checked on: 24 October 2026.