Drug Safety
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Calcium channel antagonists are used primarily for the treatment of hypertension and tachyarrhythmias. Overdose of calcium channel antagonists can be lethal. Calcium channel antagonists act at the L-type calcium channels primarily in cardiac and vascular smooth muscle preventing calcium influx into cells with resultant decreases in vascular tone and cardiac inotropy and chronotropy. ⋯ Careful evaluation of asymptomatic patients, including and electrocardiogram and a period of observation, is indicated. Patients ingesting a nonsustained-release product should be observed in a monitored setting for 12 hours, while those who ingest a sustained-release preparation should be observed for no less than 24 hours. Charcoal should be given to the asymptomatic patient with a history of calcium channel antagonist overdose.
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Transdermal fentanyl is effective and well tolerated for the treatment of chronic pain caused by malignancy and non-malignant conditions when administered according to the manufacturer's recommendations. Compared with oral opioids, the advantages of transdermal fentanyl include a lower incidence and impact of adverse effects (constipation, nausea and vomiting, and daytime drowsiness), a higher degree of patient satisfaction, improved quality of life, improved convenience and compliance resulting from administration every 72 hours, and decreased use of rescue medication. Transdermal fentanyl is a useful analgesic for cancer patients who are unable to swallow or have gastrointestinal problems. ⋯ Cognitive and physical impairments such as confusion and abnormal co-ordination can occur with transdermal fentanyl. Therefore, patients should be instructed to refrain from driving or operating machinery immediately following the initiation of transdermal fentanyl, or after any dosage increase. Patients may resume such activities once the absence of these potential adverse effects is documented.
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Review Case Reports
Safety of thrombolysis during cardiopulmonary resuscitation.
The prognosis is generally poor for patients who experience a cardiac arrest. The most common causes of sudden cardiac arrest are massive pulmonary embolism (PE) and acute myocardial infarction (MI). While thrombolysis is a first-line treatment option in massive PE and acute MI, cardiopulmonary resuscitation (CPR) has been regarded as a relative contraindication for thrombolysis because of the anticipated bleeding risk caused by traumatic cardiocompressions. ⋯ In addition, not enough controlled clinical trials have yet been conducted. Therefore, data from large randomised, multicentre studies are needed to definitely answer the question of the relationship between safety and efficacy of this promising treatment option. We conclude that the currently available data do not indicate that thrombolysis contributes to a significant increase in bleeding complications when administered during CPR.
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Deferiprone is the only orally active iron-chelating drug to be used therapeutically in conditions of transfusional iron overload. It is an orphan drug designed and developed primarily by academic initiatives for the treatment of iron overload in thalassaemia, which is endemic in the Mediterranean, Middle East and South East Asia and is considered an orphan disease in the European Union and North America. Deferiprone has been used in several other iron or other metal imbalance conditions and has prospects of wider clinical applications. ⋯ New oral iron-chelating drugs are being developed, but even if successful these are likely to be more expensive than deferiprone and are not likely to become available in the next 5-8 years. About 25% of treated thalassaemia patients in Europe and more than 50% in India are using deferiprone. For most thalassaemia patients worldwide who are not at present receiving any form of chelation therapy the choice is between deferiprone and fatal iron toxicity.
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Glaucoma comprises a heterogeneous group of diseases that have in common a characteristic optic neuropathy and visual field defects, for which elevated intraocular pressure is the major risk factor. The level of intraocular pressure within the eye depends on the steady state of formation and drainage of the clear watery fluid, called the aqueous humour, in the anterior chamber of the eye. An obstruction in the circulatory pathway of aqueous humour causes an elevation in intraocular pressure. ⋯ In this article, the mechanism and management of drug-induced glaucomatous disease of the eye are emphasised. Although the product package insert may mention glaucoma as a contraindication or as an adverse effect, the type of glaucoma is usually not specified. Clinicians should be mindful of the possibility of drug-induced glaucoma, whether or not it is listed as a contraindication and, if in doubt, consult an ophthalmologist.