Safety of non-steroidal anti-inflammatory drugs during pregnancy and lactation

Plasma and Milk Pharmacokinetics and Estimated Milk Withdrawal Time of Tolfenamic Acid in Lactating Sheep

OBJECTIVE

This study aimed to investigate the plasma and milk pharmacokinetics, as well as the withdrawal time (WT) from milk of tolfenamic acid (2 and 4 mg/kg) following intravenous (IV) administration to eight healthy lactating Akkaraman sheep.

METHODS

The trial was conducted in two periods in accordance with a crossover pharmacokinetic design. The concentrations of tolfenamic acid in the plasma and milk were determined using high-pressure liquid chromatography and evaluated using non-compartmental analysis. The WT of tolfenamic acid in milk was calculated using the WT 1.4 software.

RESULTS

Compared to the 2 mg/kg dose, plasma volume of distribution at steady state (from 0.43 to 0.50 L/kg), terminal elimination half-life (from 2.41 to 4.14 h) and dose-normalized area under the plasma concentration-time curve (AUC0-∞, from 9.46 to 30.11 h µg/mL) increased, whereas total body clearance (from 0.21 to 0.13 L/h/kg) decreased at the 4 mg/kg dose. The peak milk concentration (Cmax) and AUC0-∞ values in milk were 0.26 µg/mL and 0.28 h µg/mL, respectively, for 2 mg/kg, and 0.43 µg/mL and 0.55 h µg/mL, respectively, for 4 mg/kg. Although the dose-normalized Cmax of milk decreased depending on the dose, no difference was observed in dose-normalized AUC0-∞. The AUC0-∞ milk/AUC0-∞ plasma ratio was 0.03 for 2 mg/kg and 0.02 for 4 mg/kg. The WT values calculated for milk at dosages of 2 and 4 mg/kg were 3 and 4 h, respectively.

CONCLUSIONS

A decrease in plasma elimination and an increase in plasma concentration of tolfenamic acid were observed depending on the dose. Tolfenamic acid lowly passed into sheep's milk at 2 and 4 mg/kg doses. This study may provide valuable information for clinicians' decision-making processes.

Disease specific problems related to drug therapy in pregnancy

Rheumatic diseases occur frequently in women of childbearing years necessitating drug treatment also during a concurrent pregnancy in order to control maternal disease activity and to ensure a successful pregnancy outcome. This survey reviews maternal and fetal side effects of nonsteroidal anti-inflammatory drugs (NSAID) and immunosuppressive agents in pregnant patients. The classic nonselective nonsteroidal anti-inflammatory drugs are not teratogenic, but given in late pregnancy they can induce renal and cardiac side effects in the fetus. Similar effects must be expected of the new, selective Cox2-inhibitors. NSAID should therefore be stopped by gestational week 32. Corticosteroids are frequently necessary to control rheumatic disease flares and for prevention of serious organ manifestations. However, due to an increased risk of oral clefts, high doses (1-2 mg/kg) should be avoided in the first trimester. Among disease modifying drugs, sulfasalazine and antimalarials have the safest record. Cyclosporine and azathioprine can be given throughout pregnancy if disease control requires it. Insufficient data exist for treatment of pregnant patients with TNF-inhibitors and mycophenolate mofetil. The severity of the disease under treatment decides if continuation of one of these drugs is justified. Prophylactic withdrawal of drugs before pregnancy is mandatory for leflunomide and the cytotoxic agents methotrexate and cyclophosphamide. Prepregnancy counselling and careful monitoring during pregnancy help to tailor necessary drug treatment for the benefit of mother and child.

Sulindac and sulindac metabolites in nipple aspirate fluid and effect on drug targets in a phase I trial

Regular use of nonsteroidal anti-inflammatory drugs (NSAID) has been associated with reduced risk of breast cancer. Sulindac, a nonselective NSAID with both cyclooxygenase-2-dependent and -independent activities, is a candidate for breast chemoprevention. We conducted a phase Ib trial in 30 women at increased risk for breast cancer to evaluate the breast tissue distribution of sulindac at two dose levels (150 mg daily and 150 mg twice daily for 6 weeks), using nipple aspirate fluid (NAF) as a surrogate of breast tissue drug exposure. We also explored the effect of sulindac on drug-induced biomarkers in NAF. We show that sulindac and its metabolites partition to human breast as measured by NAF levels. Sulindac intervention did not decrease 13,14-dihydro-15-keto prostaglandin A(2), a stable derivative of prostaglandin E(2), in NAF, but exposure was associated with a significant trend towards higher levels of growth differentiation factor 15 in NAF in women receiving 150 mg twice daily (P = 0.038). These results are the first to show partitioning of sulindac and metabolites to human breast tissue and the first evidence for a potential dose-dependent effect of sulindac on growth differentiation factor 15 levels in NAF.

Anti-inflammatory pharmacotherapy during pregnancy

NSAIDs or cyclooxygenase inhibitors (COX inhibitors), including aspirin, are widely used to treat pain, fever and the articular symptoms of chronic rheumatic diseases. Manifestations of connective tissue or autoimmune diseases are commonly treated with glucocorticosteroids. The effect and side effects of NSAIDs depend on the isoforms of cyclooxygenases that they preferentially or selectively inhibit. The use of COX inhibitors has recently been associated with infertility and miscarriage. The classical nonselective COX inhibitors, including aspirin, do not increase the risk of congenital malformations in humans but administered in the latter part of gestation, they can affect pregnancy and the fetus. The ability of nonselective and selective COX inhibitors to prolong gestation has been used by obstetricians to inhibit premature delivery. The vascular effects of prostaglandin inhibitors can cause constriction of the fetal ductus arteriosus and reduce renal blood flow. These complications have been described for most nonselective COX inhibitors but are increasingly reported also for the selective COX-2 inhibitors. Aspirin, which causes irreversible inhibition of cyclooxygenases, differs from other NSAIDs with regard to indication, effects and side effects. Prematurity, which is increased in pregnancies of women with connective tissue diseases, is an additional risk factor for adverse effects of antenatal exposure to NSAIDs. Therefore, treatment with COX inhibitors should be discontinued at week 32 of gestation. The ability of NSAIDs to compromise reproductive function by inhibition of ovulation and as causative agents for miscarriage is still under debate. Glucocorticosteroids given in early pregnancy are a risk factor for the development of oral clefts. Therefore, the daily dose should be kept to <or= 15 mg during the first trimester. High doses of glucocorticosteroids in the second and third trimester are reserved for flares of autoimmune diseases. Intrauterine fetal growth restriction and premature delivery are possible side effects of high doses.

Drugs in pregnancy. Rheumatological disorders

Rheumatic diseases occur frequently in women of childbearing years, necessitating drug treatment during a concurrent pregnancy in order to control maternal disease activity and to ensure a successful pregnancy outcome. Inflammatory rheumatic diseases with mainly musculoskeletal involvement may cause acute episodes of arthritis. Autoimmune, systemic diseases may flare with manifestations of haematological, dermatological or renal disease or give rise to thromboembolism during pregnancy. Treatment with non-steroidal anti-inflammatory drugs, corticosteroids, anticoagulants, immunosuppressive or even cytotoxic drugs may be required to acquire disease control. Unfortunately, controlled studies on the use of antirheumatic drugs during gestation exist only for a few drugs. This chapter presents data on the use of antirheumatic drugs during pregnancy, addressing the risk of teratogenicity, possible long-term effects on the infant exposed to drugs antenatally, and maternal side-effects which interfere with pregnancy. Recommendations for pre-pregnancy counselling and necessary adjustment of drug treatment before and during pregnancy are given.

Spondyloarthritides in females

Few studies have been performed regarding clinical, radiological and prognostic features of females with spondyloarthropathies other than ankylosing spondylitis (AS). In AS, clinical manifestations appear similar in men and women, whereas radiological features appear more frequent and severe in males. However, no consistent differences in outcome and mortality between men and women have been disclosed. Although fetal outcome is not compromised in women with spondyloarthropathy (SpA), the interaction of pregnancy and SpA has been studied in detail only in AS. Spinal disease is unchanged while peripheral arthritis and uveitis are suppressed during childbearing. Due to possible maternal and fetal side-effects, NSAIDs must be discontinued during the last 8 weeks of pregnancy, but during lactation several NSAIDs can be used. Treatment with sulphasalazine is compatible with pregnancy and lactation. Children of AS patients exhibit a slightly increased risk of developing SpA later in life.