Fenoprofen

Risk Summary

Use of NSAIDs, including fenoprofen, during the third trimester of pregnancy increases the risk of premature closure of the fetal ductus arteriosus. Avoid use of NSAIDs, including fenoprofen, in pregnant women starting at 30 weeks of gestation (third trimester).

There are no adequate and well-controlled studies of fenoprofen in pregnant women. Data from observational studies regarding potential embryofetal risks of NSAID use in women in the first or second trimesters of pregnancy are inconclusive. In the general U.S. population, all clinically recognized pregnancies, regardless of drug exposure, have a background rate of 2-4% for major malformations, and 15-20% for pregnancy loss.

In animal reproduction studies, embryo-fetal lethality and skeletal abnormalities were noted in offspring of pregnant rabbits following oral administration of fenoprofen during organogenesis at 0.6 times the maximum human daily dose of 3200 mg/day. However, there were no major malformations noted following oral administration of fenoprofen calcium to pregnant rats and rabbits during organogenesis at exposures up to 0.3 and 0.6 times the maximum human daily dose of 3200 mg/day.

Based on animal data, prostaglandins have been shown to have an important role in endometrial vascular permeability, blastocyst implantation, and decidualization. In animal studies, administration of prostaglandin synthesis inhibitors such as fenoprofen, resulted in increased pre- and post-implantation loss.

Clinical Considerations

Labor or Delivery

There are no studies on the effects of fenoprofen during labor or delivery. In animal studies, NSAIDS, including fenoprofen, inhibit prostaglandin synthesis, cause delayed parturition, and increase the incidence of stillbirth.

Data

Human Data

There are no adequate and well-controlled studies of fenoprofen in pregnant women. Data from observational studies regarding potential embryofetal risks of NSAID use in women in the first or second trimesters of pregnancy are inconclusive.

Animal data

Pregnant rats were treated with fenoprofen using oral doses of 50 or 100 mg/kg (0.15 times and 0.3 times the maximum human daily dose (MHDD) of 3200 mg/day based on body surface area comparison) during the period of organogenesis. No major malformations were noted and there was no evidence of maternal toxicity at these doses, however, the exposures were below the exposures that will occur in humans.

Pregnant rabbits were treated with fenoprofen using oral doses of 50 or 100 mg/kg (0.3 times and 0.6 times the MHDD of 3200 mg/day based on body surface area comparison) during the period of organogenesis. Maternal toxicity (mortality) was noted in the high dose animals. Although no major malformations were noted, there was an increased incidence of embryo-fetal lethality and skeletal abnormalities were present at 0.6 times the MHDD.

Pregnant rats were treated from Gestation Day 14 through Post-Natal Day 20 with oral doses of fenoprofen of 6.25, 12.5, 25, 50, or 100 mg/kg (0.02, 0.04, 0.08, 0.15, or 0.3 times the MDD of 3200 mg/day based on body surface area comparison). All doses produced significant toxicity, including vaginal bleeding, prolonged parturition, increased stillbirths, and maternal deaths.

Pregnant rats were treated from Gestation Day 6 through Gestation Day 19 and Post Partum Day 1 to 20 (excluding parturition) with an oral dose of fenoprofen of 100 mg/kg (0.3 times the MDD of 3200 mg/day based on body surface area comparison) demonstrated only a small increase in the incidence of impaired parturition despite the presence of maternal toxicity (gastrointestinal ulceration and renal toxicity).

Risk Summary

In a published study, after a dose of 600 mg every 6 hours for 4 days in postpartum mothers, breastmilk fenoprofen levels were reportedly 1.6% of those in maternal plasma. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for fenoprofen and any potential adverse effects on the breastfed infant from the fenoprofen or from the underlying maternal condition.

Carcinogenesis

Long-term studies in animals to evaluate the carcinogenic potential of fenoprofen have not been conducted.

Mutagenesis

Studies to evaluate the genotoxic potential of fenoprofen have not been conducted.

Impairment of Fertility

Female and Male rats were treated with 60 to 70 mg/kg/day or 120 to 150 mg/kg/day fenoprofen calcium via the diet (approximately 0.2 or 0.4 times the maximum human daily dose of 3200 mg/day based on body surface area comparison, respectively). Male rats were treated from 77 days prior to mating and during mating. Female rats were treated from 14 days prior to mating and through gestation. Pregnancy rates were slightly reduced in the low and high dose groups compared to controls. There was no adverse effect on implantations, resorptions, or live fetuses.

• Cardiovascular Thrombotic Events
• GI Bleeding, Ulceration and Perforation
• Hepatotoxicity
• Hypertension
• Heart Failure and Edema
• Renal Toxicity and Hyperkalemia
• Anaphylactic Reactions
• Serious Skin Reactions
• Hematologic Toxicity

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

During clinical studies for rheumatoid arthritis, osteoarthritis, or mild to moderate pain and studies of pharmacokinetics, complaints were compiled from a checklist of potential adverse reactions, and the following data emerged. These encompass observations in 6,786 patients, including 188 observed for at least 52 weeks. For comparison, data are also presented from complaints received from the 266 patients who received placebo in these same trials. During short-term studies for analgesia, the incidence of adverse reactions was markedly lower than that seen in longer-term studies.

Adverse Drug Reactions Reported in >1% of Patients During Clinical Trials

Digestive System: During clinical trials with fenoprofen, the most common adverse reactions were gastrointestinal in nature and occurred in 20.8% of patients receiving fenoprofen as compared to 16.9% of patients receiving placebo. In descending order of frequency, these reactions included dyspepsia (10.3% fenoprofen vs. 2.3% placebo), nausea (7.7% vs. 7.1%), constipation (7% vs. 1.5%), vomiting (2.6% vs. 1.9%), abdominal pain (2% vs. 1.1%), and diarrhea (1.8% vs. 4.1%). The drug was discontinued because of adverse gastrointestinal reactions in less than 2% of patients during premarketing studies.

Nervous System: The most frequent adverse neurologic reactions were headache (8.7% vs. 7.5%) and somnolence (8.5% vs. 6.4%). Dizziness (6.5% vs. 5.6%), tremor (2.2% vs. 0.4%), and confusion (1.4% vs. none) were noted less frequently. Fenoprofen was discontinued in less than 0.5% of patients because of these side effects during premarketing studies.

Skin and Appendages: Increased sweating (4.6% vs. 0.4%), pruritus (4.2% vs. 0.8%), and rash (3.7% vs. 0.4%) were reported. Fenoprofen was discontinued in about 1% of patients because of an adverse effect related to the skin during premarketing studies.

Special Senses: Tinnitus (4.5% vs. 0.4%), blurred vision (2.2% vs. none), and decreased hearing (1.6% vs. none) were reported. Fenoprofen was discontinued in less than 0.5% of patients because of adverse effects related to the special senses during premarketing studies.

Cardiovascular: Palpitations (2.5% vs. 0.4%). Fenoprofen was discontinued in about 0.5% of patients because of adverse cardiovascular reactions during premarketing studies.

Miscellaneous: Nervousness (5.7% vs. 1.5%), asthenia (5.4% vs. 0.4%), peripheral edema (5.0% vs. 0.4%), dyspnea (2.8% vs. none), fatigue (1.7% vs. 1.5%), upper respiratory infection (1.5% vs. 5.6%), and nasopharyngitis (1.2% vs. none).

Adverse Drug Reactions Reported in <1% of Patients During Clinical Trials

Digestive System: Gastritis, peptic ulcer with/without perforation, gastrointestinal hemorrhage, anorexia, flatulence, dry mouth, and blood in the stool. Increases in alkaline phosphatase, LDH, SGOT, jaundice, and cholestatic hepatitis, aphthous ulcerations of the buccal mucosa, metallic taste, and pancreatitis.

Cardiovascular: Atrial fibrillation, pulmonary edema, electrocardiographic changes, and supraventricular tachycardia.

Genitourinary Tract: Renal failure, dysuria, cystitis, hematuria, oliguria, azotemia, anuria, interstitial nephritis, nephrosis, and papillary necrosis.

Hypersensitivity: Angioedema (angioneurotic edema).

Hematologic: Purpura, bruising, hemorrhage, thrombocytopenia, hemolytic anemia, aplastic anemia, agranulocytosis, and pancytopenia.

Nervous System: Depression, disorientation, seizures, and trigeminal neuralgia.

Special Senses: Burning tongue, diplopia, and optic neuritis.

Skin and Appendages: Exfoliative dermatitis, toxic epidermal necrolysis, Stevens-Johnson syndrome, and alopecia.

Miscellaneous: Anaphylaxis, urticaria, malaise, insomnia, tachycardia, personality change, lymphadenopathy, mastodynia, and fever.