Co-administration of Tapentadol (Palexia) with other medicines linked to risk of seizures and reports of serotonin syndrome

  • Drug Updates
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Tapentadol (Palexia), an opioid analgesic indicated for moderate to severe pain in adults and children aged ≥ 2 years. Tapentadol is also indicated in adults only for the management of severe chronic pain that can be adequately managed only with opioid analgesics.

Risk of seizures is a recognised ADR for all opioid medicines. However, a recent EU review of safety data for tapentadol raised urge for strengthened advice about the risk of seizures. Approximately half of the identified reports of seizure reflected co-administration of tapentadol with at least one other drug known to lower seizure threshold like selective serotonin-reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants, and antipsychotics. Tapentadol should be used with care in patients with a history of seizure disorders or epilepsy because of the increased risk of seizures. Strengthened warnings on seizure risk have been added to the summary of product characteristics and patient information leaflets.

There are reports of serotonin syndrome associated with co-administration of tapentadol and antidepressants, such as serotonin reuptake inhibitors (SSRIs), serotonin-noradrenaline reuptake inhibitors (SNRIs), tricyclic antidepressants and antipsychotics.

Serotonin syndrome is likely when one of the following is observed:

  • Spontaneous clonus
  • Inducible or ocular clonus with agitation or diaphoresis (sweating)
  • Tremor and hyper-reflexia
  • Hypertonia and body temperature higher than 38°C and inducible ocular clonus

Rapid improvement is expected when serotoninergic medicines are withdrawn with supportive symptomatic care. The continued use of tapentadol must be evaluated on an ongoing basis. Withdrawal symptoms can occur with abrupt cessation of treatment. See the summary of product characteristics for tapentadol for details of other interactions, including advice to avoid monoamine oxidase inhibitors with tapentadol because of the potential for hypertensive crisis.

Healthcare professionals are advised to report suspected adverse drug reactions, including those resulting from interactions between drugs via the Yellow Card Scheme.