Diclofenac dosage

Figure 6.43 H spectrum of diclofenac glucuronide obtained after single trapping from a 100 pi injection of female urine 4 h after dosage of 50 mg of diclofenac. The spectrum was recorded using a cryogenic flow probe at 600 MHz. The spectrum indicates that the sensitivity is sufficient to run aU two-dimensional experiments needed for structure elucidation. Reproduced from [82] with permission from Elsevier.

Osteoarthritis - 100 to 150 mg/day in divided doses (50 mg twice/day or 3 times/day [diclofenac sodium or potassium] or 75 mg twice/day [diclofenac sodium]). Dosages greater than 200 mg/day have not been studied. 

Eideriy Age appears to increase the possibility of adverse reactions to NSAIDs. The risk of serious ulcer disease is increased this risk appears to increase with dose. Ketorolac is cleared more slowly by the elderly use caution and reduce dosage. Pregnancy Category B (ketoprofen, naproxen, naproxen sodium, flurbiprofen, diclofenac, fenoprofen, ibuprofen, indomethacin, meclofenamate, sulindac). 

Diclofenac is a phenylacetic acid derivative that is relatively nonselective as a COX inhibitor. Pharmacokinetic and dosage characteristics are set forth in Table 36-1. 

Diclofenac, an indolacetic acid derivative, is considered to be one of the strongest nonsteroidal antiphlogistics. It is administered intramuscularly in cattle and swine at a dosage of 2.5 mg/kg bw/day for 7-21 days. 

T. Kubala, B. Gamblhir, and J. I. Borst, A specific stability indicating HPLC method to determine diclofenac in raw materials and pharmaceutical solid dosage forms, Drug Dev. Ind. Pharm, 19 749(1993). 

The stability, both chemical and physical, of a drug may be enhanced or retarded by salt formation. For example, solid dosage forms of diclofenac contain salt forms rather than the less stable free acid. Although salt formation may result in improved dissolution rate and bioavailability of a poorly water-soluble compound, the preparation of stable salt forms for some drugs may not be feasible and the free acid or base forms may be preferred. For example, the base form of a-pentyl-3-(2-quinolinylmethoxy)benzenemethanol was selected for dosage form design because of the physical instability of its hydrochloride salt. ... 

You need to check that the prescription is legal and the dose is safe and suitable for the patient (i.e. it can be dispensed). You notice that the dose is outside the normal dosage recommendations for diclofenac. From the patient medication record it appears that Mr Jones has not had diclofenac before, but you do go out and ask him. 

The dissolution test is conducted over a 7-h time period with aliquots of sample taken every hour. In contrast, diclofenac sodium is available in an extended-release form. The dissolution test is conducted over an 18-h period in which multiple samples are taken, with a change in the dissolution media to simulate a change from the stomach to the gastrointestinal tract. The purpose of dissolution testing is to ensure that the active ingredient is being released from the dosage form at an appropriate time. 

The manufacturer of spirapril briefly noted in a review that there was no relevant pharmacokinetic interaction between spirapril and diclofenac. Oxaprozin 1.2 g daily for 3 weeks did not affect the pharmacokinetics of enalapril 10 to 40 mg daily in 29 patients with hypertension. A brief mention is made in a review that, in healthy subjects, the pharmacokinetics of ramipril were unaffected by indometacin [dosage not stated] given for 3 days. ... 

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