For how long does tramadol (opioid analgesic) and paracetamol (acetaminophen) 37.5/325 provide relief from back pain?

Duration of Pain Relief from Tramadol and Paracetamol (37.5/325) for Back Pain

Tramadol (37.5 mg) and paracetamol (325 mg) combination provides pain relief for 4-6 hours, with treatment typically recommended for up to 3 months for conditions like back pain. 1

Pharmacology and Duration of Action

• Tramadol is a centrally acting synthetic opioid analgesic that works through two complementary mechanisms: binding to μ-opioid receptors and inhibiting reuptake of norepinephrine and serotonin 2
• Analgesia begins approximately within one hour after administration and reaches peak effect in approximately 2-3 hours 2
• The combination of tramadol with paracetamol exploits complementary mechanisms of action, with paracetamol providing rapid onset and tramadol offering more prolonged analgesic effect 3
• For back pain management, the medication is typically administered every 4-6 hours as needed for pain relief, not exceeding 400 mg of tramadol per day 2

Evidence for Duration in Back Pain Management

• In clinical practice, tramadol/paracetamol (37.5 mg/325 mg) is typically dosed every 6 hours (4 times daily) for back pain management 1
• Studies examining tramadol for osteoarthritis showed that dosing ranged from 37.5 mg (combined with 325 mg of paracetamol) once daily to 400 mg in divided doses, with an average follow-up period of 35 days (range 7-91 days) 1
• The combination provides both immediate and sustained pain relief, with effects lasting for at least 6 hours after administration 4
• For chronic conditions like back pain, the medication can be taken for up to 3 months, showing improvements in pain, stiffness, function, and overall well-being 1

Efficacy for Back Pain

• Patients on tramadol demonstrated a decrease in pain, improvement in stiffness, and improvement in function and overall well-being, though benefits remain modest with a 12% relative decrease in pain intensity 1
• In comparative studies for chronic low back pain, tramadol/paracetamol (37.5 mg/325 mg) showed comparable efficacy to codeine/paracetamol combinations, with equivalent mean doses of 3.5 tablets daily 4
• For acute non-low back musculoskeletal pain, moderate-certainty evidence indicates that tramadol alone did not show statistically significant pain reduction at less than 2 hours compared with placebo 1
• However, high-certainty evidence showed that acetaminophen plus opioids reduced pain at 1 to 7 days 1

Dosing Considerations

• For patients with moderate to moderately severe chronic pain not requiring rapid onset, initiate with a titration regimen to improve tolerability 2
• The total daily dose may be increased by 50 mg every 3 days as tolerated to reach 200 mg/day 2
• After titration, tramadol 50 to 100 mg can be administered as needed for pain relief every 4 to 6 hours, not exceeding 400 mg/day 2
• For elderly patients over 75 years old, total daily dose should not exceed 300 mg 2
• In patients with renal impairment (creatinine clearance <30 mL/min), increase dosing interval to 12 hours with maximum daily dose of 200 mg 2

Safety Considerations and Side Effects

• Common side effects include nausea, vomiting, dizziness, headache, drowsiness, and constipation 5
• Tramadol carries a higher risk of drug interactions than codeine 5
• When compared to codeine/paracetamol combinations, tramadol/paracetamol showed lower rates of somnolence and constipation 4, 3
• Tramadol has reduced respiratory and gastrointestinal depressive effects compared to other opioids 6
• The risk of abuse appears considerably less than with traditional opioid analgesics, though monitoring is still recommended 6

Clinical Application

• Tramadol/paracetamol should be considered as a second or third-line treatment after first-line agents like acetaminophen alone or NSAIDs for musculoskeletal pain 1, 6
• For chronic back pain management, start with the smallest effective dose and monitor response 1
• The combination may be particularly useful in mild-moderate pain where paracetamol alone is inadequate 7
• The typical mean daily dose in clinical studies for chronic musculoskeletal pain was between 3.5 and 4.2 tablets per day 7

Remember that while tramadol/paracetamol provides 4-6 hours of pain relief per dose, treatment duration should generally not exceed 3 months for chronic conditions like back pain, and the benefits must be balanced against potential risks of adverse events.