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Atypical opioid (μ-agonist + SNRI) Pregnancy: §4.6, verbatim. Pregnancy: 'Animal studies with tramadol revealed at very high doses effects on organ development, ossification and neonatal mortality. Tramadol crosses the placenta. There is inadequate evidence available on the safety of tramadol in human pregnancy. Therefore tramadol should not be used in pregnant women. Regular use during pregnancy may cause drug dependence in the foetus, leading to withdrawal symptoms in the neonate. If opioid use is required for a prolonged period in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available. Tramadol - administered before or during birth - does not affect uterine contractility. Administration during labour may depress respiration in the neonate and an antidote for the child should be readily available.' Breast-feeding: 'Administration to nursing women is not recommended as tramadol may be secreted in breast milk and may cause respiratory depression in the infant.' Fertility: 'Post marketing surveillance does not suggest an effect of tramadol on fertility. Animal studies did not show an effect of tramadol on fertility.'

Tramadol hydrochloride

Brand names: Zydol, Tramacet (combo)

Tramadol is an opioid analgesic for moderate pain that also has serotonergic and noradrenergic activity.

Adult dose

Dose: Acute pain: an initial dose of 100 mg, followed by 50 mg or 100 mg every 4–6 hours. Pain associated with chronic conditions: an initial dose of 50 mg, then titrated according to pain severity (adults and adolescents aged 12 years and over)
Route: Oral — Zydol 50 mg capsules, taken whole, not divided or chewed, with sufficient liquid, with or without food
Frequency: Every 4–6 hours for acute pain, matched to clinical need; in chronic pain, titrated to pain severity with the need for continued treatment reassessed at regular intervals
Max: Maximum total daily dose 400 mg. §4.2, verbatim: 'The total daily dose of 400 mg active substance should not be exceeded, except in special circumstances.' §4.4 restates the same figure: 'The risk may be increased when doses of tramadol exceed the recommended upper daily dose limit (400 mg).'
SCOPE — READ FIRST: this covers ORAL IMMEDIATE-RELEASE tramadol only, which is this page's primary route and formulation. The fetched SPC is for a 50 mg immediate-release capsule and contains NO parenteral and NO modified-release posology. An immediate-release regimen and its 400 mg ceiling must never be transferred to a prolonged-release product — the US extended-release label in this same bundle carries a different and lower limit ('Do not exceed a daily dose of 300 mg tramadol. Do not use with other tramadol products.'), which belongs to that ER product and not to this one. || VERBATIM §4.2 (Adults and adolescents aged 12 years and over), Acute Pain: 'An initial dose of 100mg is usually necessary. This can be followed by doses of 50 or 100mg at 4 - 6 hourly intervals, and duration of treatment should be matched to clinical need.' Pain Associated with Chronic Conditions: 'An initial dose of 50mg is advised and then titration according to pain severity. The need for continued treatment should be assessed at regular intervals as withdrawal symptoms and dependence have been reported.' || TITRATION PRINCIPLE, VERBATIM §4.2: 'The dose should be adjusted to the intensity of the pain and the sensitivity of the individual patient. The lowest effective dose for analgesia should generally be selected.' || BEFORE STARTING, VERBATIM §4.2: 'Prior to starting treatment with opioids, a discussion should be held with patients to put in place a strategy for ending treatment with tramadol in order to minimise the risk of addiction and drug withdrawal syndrome.' and 'Before initiating treatment with ZYDOL, a treatment strategy including treatment duration and treatment goals, and a plan for end of the treatment, should be agreed together with the patient, in accordance with pain management guidelines.' || STOPPING, VERBATIM §4.2: 'When a patient no longer requires therapy with tramadol, it may be advisable to taper the dose gradually to prevent symptoms of withdrawal. In absence of adequate pain control, the possibility of hyperalgesia, tolerance and progression of underlying disease should be considered.' || GERIATRIC PATIENTS, VERBATIM §4.2: 'A dose adjustment is not usually necessary in patients up to 75 years without clinically manifest hepatic or renal insufficiency. In elderly patients over 75 years elimination may be prolonged. Therefore, if necessary the dosage interval is to be extended according to the patient's requirements.' || STRENGTH IS PINNED: every figure above is stated in milligrams in the SPC, not as a capsule count, and the product itself is Zydol 50 mg Capsules. || WHY paedDose IS NULL: this SPC gives no separate paediatric regimen and no per-kilogram figure. Adolescents aged 12 years and over are dosed with the adult regimen above (§4.2 heading: 'Adults and adolescents aged 12 years and over'), and below that age, verbatim: 'ZYDOL capsules are not suitable for children below the age of 12 years.' Verify any under-18 use against a children's formulary and current prescribing references. || PROVENANCE: this draft supersedes an earlier draft of the same bundle that left the dose field empty; that draft already quoted this regimen verbatim in its notes, and the SPC doses this page's primary route and indication, so the dose field is now populated from it.

Dose adjustments

Renal

§4.2 (Renal insufficiency/dialysis and hepatic insufficiency), verbatim: 'In patients with renal and/or hepatic insufficiency the elimination of tramadol is delayed. In these patients prolongation of the dosage intervals should be carefully considered according to the patient's requirements.' §4.2 also states: 'A dose adjustment is not usually necessary in patients up to 75 years without clinically manifest hepatic or renal insufficiency.' No eGFR or creatinine-clearance threshold, and no numeric dose reduction, appears in any fetched section of this SPC.

Hepatic

§4.2 treats hepatic and renal insufficiency in a single statement, verbatim: 'In patients with renal and/or hepatic insufficiency the elimination of tramadol is delayed. In these patients prolongation of the dosage intervals should be carefully considered according to the patient's requirements.' No Child-Pugh banding and no numeric dose reduction appear in any fetched section of this SPC.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

Tramadol hydrochloride extended-release tablets should be prescribed only by healthcare professionals who are knowledgeable about the use of extended-release/long-acting opioids and how to mitigate the associated risks. (2.1) Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals. Reserve titration to higher doses of tramadol hydrochloride extended-release tablets for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. (2.1, 5) Initiate the dosing regimen for each patient individually, taking into account the patient’s …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2025-11-20. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

  • §4.3, verbatim: 'in hypersensitivity to the active substance or any of the excipients listed in section 6.1'
  • §4.3, verbatim: 'in acute intoxication with alcohol, hypnotics, analgesics, opioids, or other psychotropic medicinal products'
  • §4.3, verbatim: 'in patients who are receiving MAO inhibitors or who have taken them within the last 14 days'
  • §4.3, verbatim: 'in patients with epilepsy not adequately controlled by treatment'
  • §4.3, verbatim: 'for use in narcotic withdrawal treatment'
  • Not a UK contraindication but a §4.2 age bar: 'ZYDOL capsules are not suitable for children below the age of 12 years.' (The US extended-release label in this bundle goes further and makes this a contraindication: 'all children younger than 12 years of age' and 'post-operative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy'.)
  • Not in the UK §4.3 but contraindications in the US extended-release label in this bundle: significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment; known or suspected gastrointestinal obstruction, including paralytic ileus.
  • Not a contraindication but a §4.4 caution: 'Tramadol may only be used with particular caution in opioid-dependent patients, patients with head injury, shock, a reduced level of consciousness of uncertain origin, disorders of the respiratory centre or function, increased intracranial pressure.'
  • Not a contraindication but a §4.4 restriction: 'Concomitant use of ZYDOL and sedating medicinal products such as benzodiazepines or related substances, may result in sedation, respiratory depression, coma and death. Because of these risks, concomitant prescribing with these sedating medicinal products should be reserved for patients for whom alternative treatment options are not possible.'
  • Not a contraindication but a §4.4 restriction: 'Patients with epilepsy or those susceptible to seizures should be only treated with tramadol if there are compelling circumstances.'

Side effects

  • §4.8 summary, verbatim: 'The most commonly reported adverse reactions are nausea and dizziness, both occurring in more than 10 % of patients.'
  • Very common (≥1/10), §4.8: dizziness; nausea
  • Common (≥1/100 to <1/10), §4.8: headache; somnolence; vomiting; constipation; dry mouth; hyperhidrosis
  • Uncommon (≥1/1,000 to <1/100), §4.8: palpitation and tachycardia ('These adverse reactions may occur especially on intravenous administration and in patients who are physically stressed'); postural hypotension or cardiovascular collapse; retching; gastrointestinal discomfort (a feeling of pressure in the stomach, bloating); diarrhoea; dermal reactions (e.g. pruritus, rash, urticaria)
  • Rare (≥1/10,000 to <1/1,000), §4.8: bradycardia; increase in blood pressure; changes in appetite; respiratory depression, dyspnoea; paraesthesia, tremor, epileptiform convulsions, involuntary muscle contractions, abnormal coordination, syncope, speech disorders; hallucinations, confusion, sleep disturbance, delirium, anxiety and nightmares; miosis, mydriasis, blurred vision; motorial weakness; micturition disorders (dysuria and urinary retention — the §4.8 sentence is cut at the source-fetch limit)
  • Not known, §4.8: serotonin syndrome; hiccups; drug dependence
  • §4.8 on convulsions, verbatim: 'Convulsions occurred mainly after administration of high doses of tramadol or after concomitant treatment with medicinal products which can lower the seizure threshold.' On respiratory depression: 'If the recommended doses are considerably exceeded and other centrally depressant substances are administered concomitantly, respiratory depression may occur.'
  • §4.8 psychiatric note, verbatim: 'Psychic adverse reactions may occur following administration of tramadol which vary individually in intensity and nature (depending on personality and duration of treatment). These include changes in mood (usually elation, occasionally dysphoria), changes in activity (usually suppression, occasionally increase) and changes in cognitive and sensorial capacity.'
  • §4.8 hepatobiliary, verbatim: 'In a few isolated cases an increase in liver enzyme values has been reported in a temporal connection with the therapeutic use of tramadol.'
  • §4.4 sleep-related breathing disorders, verbatim: 'Opioids can cause sleep-related breathing disorders including central sleep apnea (CSA) and sleep-related hypoxemia. Opioid use increases the risk of CSA in a dose-dependent fashion. In patients who present with CSA, consider decreasing the total opioid dosage.'

Monitoring

  • §4.2, verbatim: 'During treatment, there should be frequent contact between the physician and the patient to evaluate the need for continued treatment, consider discontinuation and to adjust dosages if needed.'
  • §4.2 (chronic pain), verbatim: 'The need for continued treatment should be assessed at regular intervals as withdrawal symptoms and dependence have been reported.'
  • §4.4, when co-prescribed with sedating medicines, verbatim: 'The patients should be followed closely for signs and symptoms of respiratory depression and sedation. In this respect, it is strongly recommended to inform patients and their caregivers to be aware of these symptoms.'
  • §4.4 serotonin syndrome, verbatim: 'If concomitant treatment with other serotonergic agents is clinically warranted, careful observation of the patient is advised, particularly during treatment initiation and dose escalations. Symptoms of serotonin syndrome may include mental status change, autonomic instability, neuromuscular abnormalities and/or gastrointestinal symptoms. Serotonin syndrome is likely when one of the following is observed: Spontaneous clonus; Inducible or ocular clonus with agitation or diaphoresis; Tremor and hyperreflexia' — the list is cut at the source-fetch limit.
  • §4.2, verbatim: 'In absence of adequate pain control, the possibility of hyperalgesia, tolerance and progression of underlying disease should be considered.'
  • §4.4: watch for seizures — 'Convulsions have been reported in patients receiving tramadol at the recommended dose levels. The risk may be increased when doses of tramadol exceed the recommended upper daily dose limit (400 mg).'

Clinical monograph

How it works

It is a weak opioid-receptor agonist and also inhibits serotonin and noradrenaline reuptake, both contributing to analgesia.

Prescribing in practice

  • Its serotonergic action increases the risk of serotonin syndrome (e.g. with SSRIs/SNRIs) and of seizures, particularly at higher doses or with a lowered seizure threshold.
  • Like codeine it depends partly on CYP2D6 metabolism; it is a controlled drug.
  • Additive sedation and respiratory depression occur with other CNS depressants.

Monitoring

Review analgesic benefit, the serotonergic burden of co-medication, and signs of dependence.

Counselling the patient

  • Do not combine it with alcohol or other sedatives.
  • Report agitation, sweating, tremor or confusion (possible serotonin reaction).
  • Take it only as prescribed; it can be habit-forming.

Evidence & guidelines

Used for moderate pain, with particular caution about serotonin syndrome, seizures and dependence.

Reference: NICE; MHRA; FPM; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.