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 adjustments
§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.
§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 UKTramadol 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.
- Morphine Milligram Equivalents (MME) Calculator · Pain / Opioids
- Opioid Conversion / Equianalgesic Guide · Pain Management
- Numeric Rating Scale (NRS) Pain Assessment and Management · Pain Management
- Finnegan Neonatal Abstinence Scoring Tool (FNAST) · Neonatal Abstinence Syndrome
- Modified Finnegan Neonatal Abstinence Score (NAS) · Neonatal
- Withdrawal Assessment Tool (WAT-1) for Paediatric Iatrogenic Withdrawal · Critical Care