Diclofenac (Voltaren®)

Section 1.1

Midwives may independently prescribe, order and administer this drug.

(Voltaren®) is a non-steroidal anti-inflammatory (NSAID) with analgesic and antipyretic properties. While the mechanism of action is not fully understood, it is known to inhibit COX-1 and COX-2 enzymes, which results in decreased formation of prostaglandin precursors. It is commonly used post-surgically for pain relief and inflammation.

Indications and Clinical Use:

For pain relief during the postpartum period especially for reducing perineal pain and swelling from operative delivery and episiotomy. See current guidelines for drugs of choice in pregnancy and breastfeeding. Acetaminophen appears to be the best option for treatment of fever during pregnancy. Ibuprofen is the least potent of NSAIDs.

Contraindications:

Should not be given during pregnancy, especially during the last three months. Diclofenac should not be given with pre-existing cardiovascular or cerebrovascular, GI or kidney disease or any bleeding disorders. Suppositories should not be given if there is a recent history of rectal or anal bleeding or inflammatory lesions. NSAIDs should not be given to those who are asthmatic or allergic to ASA.

Warnings and Precautions:

All NSAIDs cross the human placenta in pregnancy and distribute to the fetus. NSAIDs increase the risk of premature closure or constriction of the ductus arteriosus. Avoid the concurrent use of Diclofenac with other NSAIDs. It should be used with caution if under the age of 16, or when hypertensive disorders or renal disease is present.

Pregnancy:

Human Data Suggest Risk in the 1st and 3rd Trimesters

Lactation:

Category L2 – No Human Data – Probably Compatible

Adverse Reactions:

Bleeding, hemorrhoid exacerbation, irritation and anal inflammation have been reported.
A common side effect of NSAIDs is stomach upset. Additionally mild abdominal cramping, diarrhea, dizziness and/or headaches have been reported.

Dosage and Administration:

Suppository: 50 mg, 100 mg – maximum dose 100 mg/day
Oral: 50 mg – maximum dose 100 mg/day
Oral enteric coated (delayed release): 50 mg, 75 mg

Usual dose following delivery with surgical procedures is 50 mg or 100 mg per rectum, not to exceed 100 mg/day.

Diclofenac suppositories tend to be used short-term (up to three days post-surgery), whereupon oral NSAIDs are preferred.

Onset of Action:

Suppository: Suppositories tend to have a more rapid onset of action and a slower rate of absorption compared to oral enteric coated (delayed release) tablet.
Time to peak, serum: 5 hours
Suppository: ≤1 hour; approximately two-thirds of that observed with oral tablet (equivalent 50 mg dose)
Tablet, delayed release (diclofenac sodium): 2 hours

Half-life:

2 hours

Elimination:

Urine (65%); feces (35%)