Products
The combination drug containing the active ingredients tramadol and paracetamol is commercially available in the form of film-coated tablets (Zaldiar). It has been approved in many countries since 2002. In 2014, generic versions went on sale. The effervescent tablets are out of trade.
Structure and properties
Tramadol (C16H25NO2, Mr = 263.38 g/mol) is a cyclohexanolamine and is present in drugs as tramadol hydrochloride, a white crystalline powder that is readily soluble in water. Paracetamol (C8H9NO2, Mr = 151.2 g/mol) exists as a white crystalline powder that is sparingly soluble in water.
Effects
The drug combination has analgesic and antipyretic properties but is not anti-inflammatory. Tramadol is an opioid with a dual mechanism of action: it is additionally noradrenergic and serotonergic by inhibiting neurotransmitter reuptake, thus affecting pain perception. The mechanism of action of acetaminophen has not been fully elucidated.
Indications
For symptomatic treatment of moderate to severe pain or when nonopioid analgesics are insufficiently effective. See also WHO staging regimen.
Dosage
According to the SmPC. The usual dosage is 1 to 2 film-coated tablets every 4 to 6 hours with a maximum dose of 8 tablets per day.
Contraindications
For complete precautions, see the drug label.
Adverse effects
The most common possible adverse effects include dizziness, drowsiness, and nausea, as well as headache, tremor, constipation, vomiting, diarrhea, dry mouth, dyspepsia, flatulence, abdominal pain, itching, sweating, and mood changes.