Serdep is sertraline, an SSRI antidepressant, in 50 mg and 100 mg tablets. It treats depression, anxiety disorders, panic disorder, OCD, PTSD and premenstrual dysphoric disorder. It takes weeks to work, the first fortnight is often the hardest, and stopping it abruptly causes a distinct withdrawal syndrome.
What is Serdep?
The South African Medicine Price Registry lists Serdep as Schedule 5 tablets containing sertraline at 50 mg and 100 mg.
Sertraline is a selective serotonin reuptake inhibitor (SSRI) — the most widely prescribed class of antidepressant. Nerve cells release serotonin into the gap between them and then reabsorb it. Sertraline blocks that reabsorption, so serotonin stays in the gap longer and signalling is strengthened.
The serotonin change happens within hours. The benefit takes weeks. That gap is the most important thing to understand about SSRIs, and the least intuitive. The current understanding is that the improvement comes from slower downstream adaptations — changes in receptor sensitivity and in the brain’s capacity to form new connections — rather than from the serotonin level itself.
The practical consequence is that the first two weeks are often worse than the start. Nausea, headache, restlessness, disturbed sleep and sometimes increased anxiety arrive early, while the benefit has not. Most people who stop an SSRI stop in this window, and conclude it did not work — when in truth it had not yet had the chance. Knowing this in advance is genuinely useful.
Sertraline is usually a first choice among SSRIs. It has relatively few interactions, is safe in most heart conditions, and is among the preferred options in pregnancy and breastfeeding.
Serdep, Zoloft, Sertraline Unicorn and others contain the same medicine. Being switched between brands is ordinary generic substitution.
What is Serdep commonly used for?
- Major depression, its principal use.
- Generalised anxiety disorder.
- Panic disorder, with or without agoraphobia.
- Social anxiety disorder.
- Obsessive-compulsive disorder (OCD), which often needs higher doses and longer to respond.
- Post-traumatic stress disorder (PTSD), where sertraline is one of the better-evidenced medicines.
- Premenstrual dysphoric disorder (PMDD), sometimes taken only in the second half of the cycle.
- Premature ejaculation, off-label, using the delayed-orgasm side effect deliberately.
Four things shape how well treatment goes:
Give it four to six weeks at an adequate dose. Some improvement often shows by two to three weeks — sleep and appetite usually before mood.
The dose is usually built up. Starting at 50 mg and increasing is normal, and does not mean anything has worsened. OCD in particular often needs 150 to 200 mg.
Treatment continues after you feel better. Stopping as soon as mood lifts is the commonest cause of relapse. Guidelines generally suggest at least six to twelve months beyond recovery for a first episode, longer for recurrent depression.
Medicine is not the whole treatment. Psychological therapy works at least as well as medication for many anxiety disorders, and combining them works better than either alone. Sleep, exercise and reducing alcohol all make a measurable difference — alcohol in particular directly worsens depression and blunts the medicine.
How Serdep fits into this medicine category
| Group | Examples | Notes |
|---|---|---|
| SSRIs | Sertraline (Serdep), escitalopram, fluoxetine, citalopram | First-line for depression and anxiety |
| SNRIs | Venlafaxine, duloxetine | Also help nerve pain |
| Tricyclics | Amitriptyline (Trepiline) | Older; sedating; used at low dose for nerve pain |
| SARIs | Trazodone | Sedating; often used for sleep |
| Atypicals | Mirtazapine, bupropion | Different side-effect profiles |
| Anxiolytics | Benzodiazepines | Short-term only; dependence risk |
| Sleep agents | Zolpidem (Nurika) | Short-term insomnia |
Antidepressants are not addictive, which is worth stating plainly because the fear stops many people starting. They do not produce craving, tolerance or dose escalation. They do cause discontinuation symptoms if stopped abruptly — an entirely different phenomenon, and the reason they are tapered.
See the mental health and neurology medicines hub.
What to check before using Serdep
Tell your doctor or pharmacist if you:
- Have bipolar disorder, or a family history. An antidepressant alone can trigger mania.
- Have epilepsy, liver disease or kidney disease.
- Have bleeding problems, or take warfarin, aspirin or anti-inflammatories. SSRIs affect platelets and raise bleeding risk, particularly stomach bleeding when combined with anti-inflammatories.
- Take other serotonergic medicines — tramadol, triptans, other antidepressants, linezolid, or St John’s Wort.
- Take or recently took an MAOI. A washout gap is required.
- Take pimozide, which must not be combined.
- Have glaucoma, diabetes, or low sodium, or take diuretics.
- Are under 25, where suicidal thoughts can increase early in treatment and closer monitoring is warranted.
- Are pregnant, planning pregnancy or breastfeeding. Sertraline is among the preferred options, but this needs a proper conversation, not a decision made alone.
Practical points:
- Take it at the same time each day, with or without food. Morning if it disturbs sleep; evening if it makes you drowsy.
- Expect the first two weeks to be the hardest, and report side effects rather than stopping.
- Avoid alcohol, particularly early on.
- Never stop suddenly. Taper with your doctor.
- Tell any new prescriber you take it.
Possible cautions and when to ask a pharmacist or doctor
Common effects: nausea, diarrhoea, headache, dry mouth, sweating, tremor, disturbed sleep, drowsiness or restlessness. Most settle within two to three weeks.
Sexual side effects deserve honest mention because they are common, under-discussed, and a major reason people stop without saying why. Reduced desire, difficulty reaching orgasm and erectile difficulty affect a substantial minority. They are usually reversible, and there are options — dose adjustment, timing, or switching to an antidepressant less prone to it. Raise it; your doctor will not be surprised.
Get emergency help for:
- Thoughts of harming yourself, or a marked worsening of mood, especially in the first weeks. Contact a doctor, an emergency department, or the South African Depression and Anxiety Group.
- Agitation with fever, sweating, shivering, muscle twitching, fast heartbeat and confusion — possible serotonin syndrome.
- A seizure.
- Vomiting blood or black tarry stools.
- Swelling of the face, lips or tongue, or difficulty breathing.
Seek prompt advice for:
- Confusion, marked drowsiness, headache with nausea or unsteadiness — possible low sodium, more common in older people and on diuretics.
- Unusual bruising or bleeding.
- Restlessness or an inability to sit still, which can be distressing and is treatable.
- Unusual elation, racing thoughts or reduced need for sleep — possible mania.
- A rash, or yellowing of the skin or eyes.
Contact your doctor if there is no improvement after four to six weeks, if side effects are not settling, if you want to stop — so it can be tapered — or if you become pregnant. If you have missed several days, restart and tell your doctor rather than doubling up.
Related medicine guides
Frequently asked questions
What is Serdep 50 mg used for? Depression, anxiety disorders, panic disorder, OCD, PTSD and PMDD. 50 mg is a common starting dose. It contains sertraline.
What is Serdep 100 mg used for? The same conditions at a higher dose. OCD in particular often needs 150 to 200 mg.
How long before it works? Four to six weeks for full effect, with some improvement often by two to three weeks. Sleep and appetite usually improve before mood.
Why do I feel worse at first? Early side effects — nausea, restlessness, disturbed sleep, sometimes more anxiety — arrive before the benefit. This usually settles within two weeks. Tell your doctor rather than stopping.
Is it addictive? No. It causes no craving or tolerance. But stopping suddenly causes discontinuation symptoms, so it is tapered.
Can I stop when I feel better? Not straight away. Guidelines suggest continuing at least six to twelve months after recovery for a first episode, and longer if depression has recurred.
Does it affect sex drive? It can, in a substantial minority. This is usually reversible and there are options — raise it with your doctor rather than stopping.
Can I drink alcohol? Best avoided. Alcohol worsens depression directly and blunts the medicine.
Is it safe in pregnancy? Sertraline is among the preferred antidepressants in pregnancy and breastfeeding, but discuss it with your doctor rather than deciding alone.