Ibuprofen in human milk

Interpreting the Benefit and Risk Data in Between-Drug Comparisons: Illustration of the Challenges Using the Example of Mefenamic Acid versus Ibuprofen

Evidence-based pain therapy should rely on precisely defined and personalized criteria. This includes balancing the benefits and risks not only of single drugs but often requires complex between-drug comparisons. Non-steroidal anti-inflammatory drugs (NSAIDs) have been available for several decades and their use is described in an abundance of guidelines. Most of these guidelines recommend that ‘the selection of a particular NSAID should be based on the benefit-risk balance for each patient’. However, head-to-head studies are often lacking or of poor quality, reflecting the lower standards for clinical research and regulatory approval at the time. The inconsistency of approved indications between countries due to national applications adds to the complexity. Finally, a fading research interest once drugs become generic points to a general deficit in the post-marketing evaluation of medicines. Far from claiming completeness, this narrative review aimed to illustrate the challenges that physicians encounter when trying to balance benefits and risks in a situation of incomplete and inconsistent data on longstanding treatment concepts. Ibuprofen and mefenamic acid, the most frequently sold NSAIDs in Austria, serve as examples. The illustrated principles are, however, not specific to these drugs and are generalizable to any comparison of older drugs in daily clinical practice.

Lactation and Management of Postpartum Disease

While much of the existing literature in the field of reproductive rheumatology focuses on fertility, preconception counseling, and pregnancy, there is limited information regarding the postpartum period and lactation. Evidence suggests that many rheumatologic disorders flare after delivery, which, along with limitations in medications compatible with breastfeeding, make this time period challenging for women with rheumatologic conditions. This article discusses rheumatologic disease activity during the postpartum period and reviews the safety during lactation of commonly used medications for the management of rheumatic diseases. Fortunately, many of the commonly used medications are compatible with breastfeeding.

Analgesic use - prevalence, biomonitoring and endocrine and reproductive effects

Paracetamol and NSAIDs, in particular acetylsalicylic acid (aspirin) and ibuprofen, are among the most used and environmentally released pharmaceutical drugs. The differences in international trends in the sale and consumption of mild analgesics reflect differences in marketing, governmental policies, habits, accessibility, disease patterns and the age distribution of each population. Biomonitoring indicates ubiquitous and high human exposure to paracetamol and to salicylic acid, which is the main metabolite of acetylsalicylic acid. Furthermore, evidence suggests that analgesics can have endocrine disruptive properties capable of altering animal and human reproductive function from fetal life to adulthood in both sexes. Medical and public awareness about these health concerns should be increased, particularly among pregnant women.

Nonsteroidal anti-inflammatory drugs during pregnancy and the initiation of lactation

Nonsteroidal anti-inflammatory drugs (NSAIDs) and aspirin, which are available as "over-the counter" medications in most countries, are widely used by both pregnant and lactating women. They are popular non-opioid analgesics for the treatment of pain after vaginal and operative delivery. In addition, NSAIDs are used for tocolysis in premature labor, and low-dose aspirin has a role in the prevention of preeclampsia and recurrent miscarriage in antiphospholipid syndrome. NSAIDs and aspirin may affect fertility and increase the risk of early pregnancy loss. In the second trimester their use is considered reasonably safe, but has been associated with fetal cryptorchism. In the third trimester, NSAIDs and aspirin are usually avoided because of significant fetal risks such as renal injury, oligohydramnios, constriction of the ductus arteriosus (with potential for persistent pulmonary hypertension in the newborn), necrotizing enterocolitis, and intracranial hemorrhage. Maternal administration or ingestion of most NSAIDs results in low infant exposure via breastmilk, such that both cyclooxygenase-1 and cyclooxygenase-2 inhibitors are generally considered safe, and preferable to aspirin, when breastfeeding.

Migraine therapy during pregnancy and lactation

IMPORTANCE OF THE FIELD

Migraine affects about 25% of women during childbearing years but few data are available about the risks connected with most antimigraine drugs during pregnancy.

AREAS COVERED IN THIS REVIEW

In this report, we review the available data, mainly obtained from published studies, toxicology databases and clinical guidelines, on migraine treatment during pregnancy and lactation.

WHAT THE READER WILL GAIN

The following drugs should be preferred for the treatment of acute migraine attacks in pregnant women: paracetamol, NSAIDs and sumatriptan. Migraine prophylaxis should be undertaken when patients experience at least three prolonged severe attacks a month that are particularly incapacitating or unresponsive to symptomatic therapy and likely to result in complications. Non-pharmacologic approaches should be preferred, but if they are not effective, preventive treatment should include low doses of β-blockers and amitriptyline.

TAKE HOME MESSAGE

Migraine treatment is often necessary because maternal and fetal risks related to acute attacks may be more harmful than the therapy itself, especially if they are frequent, severe and associated with nausea, anorexia, vomiting, hypotension or dehydration. If non-pharmacologic treatments do not alleviate migraine symptoms, only few drugs can be used during pregnancy and lactation.

Therapy insight: the use of antirheumatic drugs during nursing

In 90% of cases, women with rheumatoid arthritis suffer a disease flare within 3 months of delivery of their baby. Drug treatment is, therefore, required; however, such therapies have implications for mothers who decide to nurse their infants. Unfortunately, because of a paucity of data, little is known about the transfer of antirheumatic drugs into breast milk, and even less is known about whether small amounts of these agents ingested during nursing could harm the infant. Our review of the literature indicates that paracetamol, prednisone, antimalarial agents, sulfasalazine and most NSAIDs can safely be used by lactating mothers. Expert opinions differ regarding the use of azathioprine, ciclosporin, and methotrexate during lactation because of varying views on the potential for short-term and long-term adverse effects. Evidence regarding the transfer of leflunomide and biologic drugs into breast milk is insufficient; therefore, until more studies are conducted, the use of these drugs in breastfeeding mothers should be restricted. At present, many patients feel they have to choose between postpartum disease control and lactation. Extended studies of the transfer of antirheumatic drugs into breast milk and the resulting consequences are, therefore, urgently needed.

Postoperative pain management in obstetric anesthesia–new challenges and solutions

The current understanding of pain processing mechanisms, the different pharmacologic drugs, and other nonpharmacologic means that can be used to manage postobstetric operation pain are reviewed.

Adverse drug reactions in breastfed infants: less than imagined

Medication use during breastfeeding shortens the duration of breastfeeding often because of overly cautious information given by healthcare providers. No comprehensive review of the literature on infant adverse reactions from drugs in breastmilk has been published. All published studies and case reports on adverse events in infants caused by medications (excluding drugs of abuse) in breastmilk were identified and analyzed. Of 100 case reports evaluated, none were considered to be "definite" using a standard ranking scale; 47% were "probable" and 53% were "possible." Drugs with central nervous system activity accounted for half of all reports. All 3 reported fatalities involved central nervous system depressants, but each had extenuating circumstances. At least 63% of reported cases were in neonates and 78% were in infants 2 months or younger; only 4% of adverse reactions occurred in infants older than 6 months of age. Published studies expand on and generally reinforce the analysis of case reports. By taking a few simple precautions in drug selection and considering the infant's age, breastfeeding rarely needs to be discouraged or discontinued when a mother needs drug therapy.

Molecular descriptors that influence the amount of drugs transfer into human breast milk

Most drugs are excreted into breast milk to some extent and are bioavailable to the infant. The ability to predict the approximate amount of drug that might be present in milk from the drug structure would be very useful in the clinical setting. The aim of this research was to simplify and upgrade the previously developed model for prediction of the milk to plasma (M/P) concentration ratio, given only the molecular structure of the drug. The set of 123 drug compounds, with experimentally derived M/P values taken from the literature, was used to develop, test and validate a predictive model. Each compound was encoded with 71 calculated molecular structure descriptors, including constitutional descriptors, topological descriptors, molecular connectivity, geometrical descriptors, quantum chemical descriptors, physicochemical descriptors and liquid properties. Genetic algorithm was used to select a subset of the descriptors that best describe the drug transfer into breast milk and artificial neural network (ANN) to correlate selected descriptors with the M/P ratio and develop a QSAR. The averaged literature M/P values were used as the ANN's output and calculated molecular descriptors as the inputs. A nine-descriptor nonlinear computational neural network model has been developed for the estimation of M/P ratio values for a data set of 123 drugs. The model included the percent of oxygen, parachor, density, highest occupied molecular orbital energy (HOMO), topological indices (chiV2, chi2 and chi1) and shape indices (kappa3, kappa2), as the inputs had four hidden neurons and one output neuron. The QSPR that was developed indicates that molecular size (parachor, density) shape (topological shape indices, molecular connectivity indices) and electronic properties (HOMO) are the most important for drug transfer into breast milk. Unlike previously reported models, the QSPR model described here does not require experimentally derived parameters and could potentially provide a useful prediction of M/P ratio of new drugs only from a sketch of their structure and this approach might also be useful for drug information service. Regardless of the model or method used to estimate drug transfer into breast milk, these predictions should only be used to assist in the evaluation of risk, in conjunction with assessment of the infant's response.

Analgesics and breast-feeding: safety considerations

The issue of prescription of analgesics during lactation is clinically important but also complex. Most of the information available is based on single dose or short term studies, and for many drugs only a single or a few case reports have been published. As great methodological problems exist in the assessment of possible adverse drug reactions in neonates and infants, there is limited knowledge about the practical impact of the, often very low, concentrations found. Nevertheless, some recommendations can be made. Breast-feeding during maternal treatment with paracetamol (acetaminophen) should be regarded as being safe. Short term use of nonsteroidal anti-inflammatory drugs seems to be compatible with breast-feeding. For long term treatment, short-acting agents without active metabolites, such as ibuprofen, should possibly be preferred. The use of aspirin (acetylsalicylic acid) in single doses should not pose any significant risks to the suckling infant. Use of codeine is probably compatible with breast-feeding, although the effects of long term exposure have not been fully elucidated. For propoxyphene, it seems unlikely that the suckling infant will ingest amounts that will cause any detrimental effects during short term treatment. However, it cannot be excluded that significant amounts of the metabolite norpropoxyphene may arise in the suckling infant during long term exposure. Treatment of the mother with single doses of morphine or pethidine (meperidine) is not expected to cause any risk for the suckling infant. Repeated administration of pethidine, in contrast to morphine, affects the suckling infant negatively. Thus, morphine should be preferred in lactating mothers. However, during long term treatment with morphine, the importance of uninterrupted breast-feeding should be assessed on an individual basis against the potential risk of adverse drug effects in the infant. If it is decided to continue breast-feeding the infant should be observed for possible adverse effects. In general, if treatment of a lactating mother with an analgesic drug is considered necessary, the lowest effective maternal dose should be given. Moreover, infant exposure can be further reduced if breast-feeding is avoided at times of peak drug concentration in milk. As breast milk has considerable nutritional, immunological and other advantages over formula milk, the possible risks to the infant should always, and on an individual basis, be carefully weighed against the benefits of continuing breast-feeding.

An audit of mastitis in the emergency department

A medical audit was conducted in 1997 of hospital records of women attending the emergency department of the Royal Women's Hospital in Melbourne, Australia, in 1996 with a diagnosis of "mastitis." One hundred and seven women were diagnosed with mastitis; approximately half were primiparous (53%) and the median age of the baby was 14 days. Most women (69%) attended the emergency department after normal working hours. Thirty-nine percent of the women were afebrile, and only 27% had a temperature of 38.5C or higher. The majority of women were prescribed flucloxacillin. Milk culture was obtained in only 15 cases, and Staphylococcus aureus was the most common pathogen.