Drug-induced congenital defects: strategies to reduce the incidence

Structure-Activity Relationship (SAR) Model for Predicting Teratogenic Risk of Antiseizure Medications in Pregnancy by Using Support Vector Machine

Teratogenicity is one of the main concerns in clinical medications of pregnant women. Prescription of antiseizure medications (ASMs) in women with epilepsy during pregnancy may cause teratogenic effects on the fetus. Although large scale epilepsy pregnancy registries played an important role in evaluating the teratogenic risk of ASMs, for most ASMs, especially the newly approved ones, the potential teratogenic risk cannot be effectively assessed due to the lack of evidence. In this study, the analyses are performed on any medication, with a focus on ASMs. We curated a list containing the drugs with potential teratogenicity based on the US Food and Drug Administration (FDA)-approved drug labeling, and established a support vector machine (SVM) model for detecting drugs with high teratogenic risk. The model was validated by using the post-marketing surveillance data from US FDA Spontaneous Adverse Events Reporting System (FAERS) and applied to the prediction of potential teratogenic risk of ASMs. Our results showed that our proposed model outperformed the state-of-art approaches, including logistic regression (LR), random forest (RF) and extreme gradient boosting (XGBoost), when detecting the high teratogenic risk of drugs (MCC and recall rate were 0.312 and 0.851, respectively). Among 196 drugs with teratogenic potential reported by FAERS, 136 (69.4%) drugs were correctly predicted. For the eight commonly used ASMs, 4 of them were predicted as high teratogenic risk drugs, including topiramate, phenobarbital, valproate and phenytoin (predicted probabilities of teratogenic risk were 0.69, 0.60 0.59, and 0.56, respectively), which were consistent with the statement in FDA-approved drug labeling and the high reported prevalence of teratogenicity in epilepsy pregnancy registries. In addition, the structural alerts in ASMs that related to the genotoxic carcinogenicity and mutagenicity, idiosyncratic adverse reaction, potential electrophilic agents and endocrine disruption were identified and discussed. Our findings can be a good complementary for the teratogenic risk assessment in drug development and facilitate the determination of pharmacological therapies during pregnancy.

Recommendations for the use of pharmacological smoking cessation strategies in pregnant women

Maternal smoking during pregnancy causes significant fetal morbidity and is a public health problem, as 36% of women in the UK and 11% of those in the US smoke during pregnancy. Behavioural support for smoking cessation, provided outside of routine antenatal care, is effective for promoting smoking cessation by pregnant women, but relatively few pregnant women access such support. Effective pharmacological aids to smoking cessation, which have been trialled in nonpregnant populations, include nicotine replacement therapy (NRT), bupropion and varenicline; however, there is very little evidence to justify the use of these drugs in pregnancy. Also, for safety reasons, it is doubtful that definitive trials investigating the effectiveness of either bupropion or varenicline for smoking cessation will be conducted in pregnant women in the foreseeable future. In the short to medium term, research information relating to the use of these drugs in pregnancy is, therefore, likely to be derived from observational studies that are more difficult to interpret than clinical trials. This article assesses the evidence for the effectiveness and safety of using NRT, bupropion and varenicline for smoking cessation during pregnancy. The principle recommendations made are that NRT may be safer than smoking in pregnancy, and pregnant women who have unsuccessfully tried to stop smoking without pharmacotherapy may consider using NRT in subsequent quit attempts after informed discussion with their doctor. There is no evidence, however, that NRT is actually effective for smoking cessation in pregnancy. With currently available evidence, bupropion and varenicline cannot be recommended in pregnancy for smoking cessation.

Treating common problems of the nose and throat in pregnancy: what is safe?

Although all kinds of medications should be avoided during pregnancy, the majority of pregnant women receive at least one drug and 6% of them during the high-risk period of the first trimester. The aim of the present paper is to discuss the appropriate management of rhinologic and laryngeal conditions that may be encountered during pregnancy. A literature review from Medline and database sources was carried out. Related books and written guidelines were also included. Controlled clinical trials, prospective and retrospective studies, case-control studies, laboratory studies, clinical and systematic reviews, metanalyses, and case reports were analysed. The following drugs are considered relatively safe: beta-lactam antibiotics (with dose adjustment), macrolides (although the use of erythromycin and clarithromycin carries a certain risk), clindamycin, metronidazole (better avoided in the first trimester), amphotericin-B (especially in immunocompromised situations during the second and third trimester) and acyclovir. First-line antituberculous agents isoniazid, ethambutol, pyrazinamide, and ciprofloxacine in drug-resistant tuberculosis can be also used. Non-selective NSAIDs (until the 32nd week), nasal decongestants (with caution and up to 7 days), intranasal corticosteroids, with budesonide as the treatment of choice, second generation antihistamines (cetirizine in the third trimester, or loratadine in the second and third trimester), H2 receptor antagonists (except nizatidine) and proton pump inhibitors (except omeprazole) can be used to relieve patients from the related symptoms. In cases of emergencies, epinephrine, prednisone, prednisolone, methylprednisolone, dimetindene and nebulised b(2) agonists can be used with extreme caution. By contrast, selective COX-2 inhibitors and BCG vaccination are contraindicated in pregnancy. When prescribing to a pregnant woman, the safety of the materno-foetal unit is considered paramount. Although medications are potentially hazardous, misconceptions and suboptimal treatment of the mother might be more harmful to the unborn child. Knowledge update is necessary to avoid unjustified hesitations and provide appropriate counselling and treatment for pregnant women.

Treating common ear problems in pregnancy: what is safe?

In everyday practise, more than 80% of pregnant women receive one at least medication, often for ENT causes. The aim of the present paper is to review the literature on safety and administration of medical treatment for ear diseases, in pregnant women. The literature review includes Medline and database sources. Electronic links, related books and written guidelines were also included. The study selection was as follows: controlled clinical trials, prospective trials, case-control studies, laboratory studies, clinical reviews, systematic reviews, metanalyses, and case reports. The following drugs are considered relatively safe: beta-lactam antibiotics (with dose adjustment), macrolides (although the use of erythromycin and clarithromycin carries a certain risk), and acyclovir. Non-selective NSAIDs (until the 32nd week), nasal decongestants (with caution and up to 7 days), intranasal corticosteroids, with budesonide as the treatment of choice, first generation antihistamines, or cetirizine (third trimester) and loratadine (second and third trimester) from the second generation, H2 receptor antagonists (except nizatidine) and proton pump inhibitors (except omeprazole), can be used to relieve patients from the related symptoms. Meclizine and dimenhydrinate, as antiemetics in vertigo attacks; metoclopramide, vitamin B6 and ginger rhizome, alternatively. Low-dose diazepam and diuretics in severe cases of Meniere's disease (with caution). Systemic administration of prednisone and prednisolone can be considered in selected cases. By contrast, selective COX-2 inhibitors, betahistine and vasodilating agents are contraindicated in pregnancy. Since otologic and neurotologic manifestations during pregnancy tend to seriously affect the quality of life of the expectant mothers, ENT surgeons should familiarise themselves with the basic guidelines and safety precautions for any related medication, in order to provide appropriate treatment.

All-trans retinoic acid inhibits vascular endothelial growth factor expression in a cell model of neutrophil activation

Infiltrating neutrophil granulocytes are a particularly rich source of vascular endothelial growth factor (VEGF) in the endometrium and may contribute to the angiogenesis of endometriosis lesions. The objective of this study is to evaluate the expression and regulation of VEGF in endometrial neutrophils and in a model of neutrophil differentiation relevant to endometriosis. Immunohistochemistry was performed on endometriosis patient biopsies and cultured neutrophil-like HL-60 cells were assessed. The study was set in a reproductive biology division within an academic medical center. Endometrial biopsies were performed on women with endometriosis and HL-60 cells were treated with all-trans retinoic acid (atRA) and dimethyl sulfoxide in vitro. Immunofluorescence histochemistry, VEGF mRNA and protein quantification, and transfection studies of VEGF gene promoter-luciferase constructs were all main outcome measures. Immunofluorescence studies verified the presence of neutrophils in eutopic endometrium from women with endometriosis. Examination of the regulation of VEGF using differentiated HL-60 cells as a model, revealed that atRA induced a dose- and time-dependent suppression of VEGF mRNA and protein. Transient transfection, truncation, EMSA, and site-directed mutagenesis of human VEGF promoter-luciferase constructs in HL-60 cells indicated that atRA repressed VEGF gene transcription via a direct repeat 1 element located between -443 and -431 bp relative to the transcription initiation site. Because retinoic acid is synthesized de novo in endometrial cells under the influence of progesterone, our findings suggest that the up-regulated VEGF and angiogenesis in tissue from women with endometriosis may reflect failure of neutrophil differentiation in these cases, and provide a rationale for retinoid therapy in this condition.

Risk of drug-induced congenital defects

Defects attributable to drug therapy represent about 1% of congenital defects of known aetiology. This means that a precautionary attitude and correct use of drugs in fertile, and especially pregnant, women is a feasible form of prevention. Drugs currently in use with proven teratogenic effect number approximately 25, but new pharmaceutical drugs are constantly in preparation. Recognition of a drug-induced teratogenic effect is a complex procedure taking into account not only experimental animal data but also experience in humans. Considering that 40% of pregnancies are not planned, it follows that any drug with known or suspected teratogenic potential must be used only under strict medical control. Also, adequate knowledge on potential teratogenicity of a drug permits modification of therapy before conception. It goes without saying that any drug should be used during pregnancy only if it is essential, and it would be prudent to use only those where adequate information is provided and prior clinical experience is available. Teratology Information Services can assist both physicians and patients when any doubt exists.

Can We Ensure the Safe Use of Known Human Teratogens?

The prescription of known teratogenic medications requires a careful balance between allowing women access to medications that they might need and avoiding unnecessary exposure to these medications during pregnancy because of their devastating fetal effects. Isotretinoin, a potent human teratogen, is of particular concern because of its widespread use among reproductive-aged women and the dramatic increase in use from 1992 through 2000. A revised risk management system was implemented in 2002 because of concerns about the continued occurrence of isotretinoin-exposed pregnancies. However, the recent approval of three generic versions of isotretinoin in the US has further complicated risk management and raises concerns that use might increase further if the lower cost of generics serves to increase accessibility. There are now four separate isotretinoin risk management systems in the US, each with its own distinct packaging, though the requirements for and substance of each are identical. Some additional concrete steps could be taken to minimise any unnecessary use of isotretinoin and help allow an adequate assessment of the current risk management systems. In addition to being familiar with and following all aspects of the current risk management system, physicians could choose to limit the use of isotretinoin to those who meet the labelled indications in order to reduce the number of exposed pregnancies. All four companies currently marketing isotretinoin in the US could jointly and voluntarily establish a consolidated, mandatory registration and follow-up of all women of reproductive potential who receive an isotretinoin prescription. Mandatory registration has many challenges, but it could allow a clear accounting of the total number of women for whom follow-up information is and is not available. Although the companies cannot be legally compelled to use a consolidated approach, the use of a single registry for the originator's product and all generic brands would allow identification of duplicates and also avoid the confusion that is introduced by providing materials that not only look different, but also have different addresses, contact information and names for participation in follow-up surveys. This is particularly important because women might take more than one version of isotretinoin during a single course of therapy or might receive a different programme's materials from their doctor than from the pharmacy. Though the introduction of generic versions of isotretinoin further complicates risk management, the companies marketing isotretinoin have an opportunity to work together to demonstrate their commitment to both limit the occurrence of exposed pregnancies and conduct a meaningful evaluation of the occurrence of pregnancies exposed to isotretinoin.

Topical nonsteroidal anti-inflammatory drugs for ophthalmic use: a safety review

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used agents that despite chemically heterogeneity, share similar therapeutic properties and adverse effects. Topical ophthalmic NSAIDs are limited to the relatively water soluble phenylacetic and phenylalkanoic acids as well as indole derivatives, which are more suitable for ophthalmic use. Topical ophthalmic NSAIDs are commonly used in the treatment of post-operative inflammation following cataract extraction and various surgical refractive procedures. They are also used in the prevention and treatment of cystoid macular oedema and for the treatment of allergic conjunctivitis. Absorption of topical ophthalmic NSAIDs through the nasal mucosa results in systemic exposure and the occurrence of adverse systemic events, including exacerbation of bronchial asthma. Local irritant effects of topical ophthalmic NSAIDs include conjunctival hyperaemia, burning, stinging and corneal anaesthesia. A more serious complication involves the association of topical ophthalmic NSAIDs with indolent corneal ulceration and full-thickness corneal melts. Analysis of NSAID-associated corneal events implicates the now defunct generic dicolfenac product, diclofenac sodium ophthalmic solution as the agent primarily responsible. However, these events generated a renewed interest in the safety of ophthalmic NSAIDs and a scrutiny of the pharmacology regarding NSAID action in the eye. An elucidation of possible pharmacodynamic explanations of NSAID-induced corneal injury includes the role of epithelial hypoxia, which not only appears to aid in determining the metabolic destination of arachidonate, it may play a key role in orchestrating a novel inflammatory response unrelated to prostanoid formation. The use of NSAIDs under conditions of corneal hypoxia may therefore not only result in a disappointing therapeutic response, it may result in a paradoxical inflammatory exacerbation. Other potential mechanisms include the relationship between NSAIDs and corneal matrix metalloproteinase and direct toxicity due to cytotoxic excipients such as surfactants, solubilisers and preservatives found in topical NSAID ophthalmic preparations. In general, ophthalmic NSAIDs may be used safely with other ophthalmic pharmaceuticals; however, concurrent use of agents known to adversely effect the corneal epithelium, such as gentamicin, may lead to increased corneal penetration of the NSAID. The concurrent use of NSAIDs with topical corticosteorids in the face of significant pre-existing corneal inflammation has been identified as a risk factor in precipitating corneal erosions and melts and should be undertaken with caution. Until clinical evidence dictates otherwise, data supporting theories of potential pharmacodynamic mechanisms of NSAID injury do not alter the favorable benefit-risk ratio of ophthalmic NSAID use when employed in an appropriate and judicious manner.