Who is an NRI

First MOR-NRI convinces with good analgesia

The analgesic is not a prodrug and does not form any analgesic active metabolites. 97% of the substance is metabolized, mainly through inactivation via glucuronidation. There is only a slight oxidative metabolism via the cytochrome P450 system. As a result, the active ingredient has only a low potential for interaction and can be easily combined with other drugs. The albumin-plasma protein binding of tapentadol is 20% and the active substance has a high volume of distribution. 99% of it is excreted in the urine over 72 hours. The AUC and Cmax increased slightly when the prolonged release tablets were administered after a high-calorie, high-fat breakfast. No clinical relevance was ascribed to this as it lies within the normal interpersonal variability of the pharmacokinetic parameters of tapentadol, therefore the prolonged-release tablets can be taken with or without food.

For neuropathic and nociceptive pain

The MOR-NRI has proven its analgesic effectiveness with good tolerability in clinical studies for nociceptive and neuropathic pain (chronic non-tumor-related back pain or pain due to osteoarthritis of the knee joint). Compared to oxycodone, the equianalgesic dosage resulted in significantly fewer side effects. In around 50% fewer patients, vomiting and constipation occurred under the MOR-NRI and the proportion of patients with nausea and itching was around 40% lower, which led to a significantly lower rate of treatment discontinuations due to side effects. Compared to oxycodone, tapentadol also showed benefits in seven out of eight areas of the SF36 for measuring quality of life.

The setting to tapentadol should start with a low dose of 50 mg twice daily in opioid-naïve patients. The dose can then be increased within three days, adapted to the individual situation, with 100 mg / d twice being determined as the smallest effective dose in the studies. In pain patients who have already been pretreated with a highly effective opioid, equianalgesic doses should be started and any concomitant medication, e.g. anticonvulsants, should be maintained. There are currently limited data available for the treatment of cancer pain.

Source: Specialist information Palexia® retard, as of August 2010, Dr. med. Dipl. Soz. Reinhardt Sittl, Erlangen; Dr. med. Kai-Uwe Kern, Wiesbaden; Dr. med. Johannes Horlemann, Kevelaer: Symposium "Therapy of chronic, severe pain: what is important?" at the 117th Congress of the German Society for Internal Medicine, Wiesbaden, May 2, 2011, organized by Grünenthal GmbH, Aachen.

Medical journalist Christine Vetter

DAZ 2011, No. 24, p. 38