Pulmonary complications from ophthalmic preparations

Timolol-induced interstitial lung disease

Timolol maleate is a non-selective beta-adrenergic receptor blocking agent with demonstrated efficacy in the treatment of open-angle glaucoma. A 76 year old female who presented with productive cough, progressive dyspnea and hypoxia after starting timolol maleate opthalamic drops following glaucoma surgery. The patient was diagnosed with interstitial lung disease secondary to timolol treatment and after cessation of the offending agent along with corticosteroid treatment, symptoms improved drastically. Elimination of other possible causes of disease along with evolution of radiological and functional signs left us with a diagnosis of timolol-induced interstitial lung disease. To our knowledge, this is the second reported case of timolol-induced interstitial lung disease.

Gastroesophageal reflux in cystic fibrosis: current understandings of mechanisms and management

Cystic fibrosis (CF) is an inherited disease that affects both the lungs and the digestive system in children and adults. Thick mucus fills the gut and blocks lumens of the pancreas and hepatobiliary systems, creating insufficient pancreas function and liver disease. Chronic gastrointestinal (GI) complications, including intestinal obstruction, occur in neonates, and poor digestion and gastroesophageal reflux disease (GERD) in children. Although GI symptoms tend to improve with age, CF and associated GERD eventually create respiratory insufficiency; the only available treatment option at this stage is a bilateral lung transplant, which carries considerable morbidity and mortality. While GERD may reoccur as a complication of lung transplantation, GERD symptoms are often reduced following a fundoplication.

Developing paediatric medicines: identifying the needs and recognizing the challenges

There is a significant need for research and development into paediatric medicines. Only a small fraction of the drugs marketed and utilized as therapeutic agents in children have been clinically evaluated. The majority of marketed drugs are either not labelled, or inadequately labelled, for use in paediatric patients. The absence of suitable medicines or critical safety and efficacy information poses significant risks to a particularly vulnerable patient population. However, there are many challenges associated with developing medicines for the paediatric population and this review paper is intended to highlight these. The paediatric population is made up of a wide range of individuals of substantially varied physical size, weight and stage of physiological development. Experimentation on children is considered by many to be unethical, resulting in difficulties in obtaining critical safety data. Clinical trials are subject to detailed scrutiny by the various regulatory bodies who have recently recognized the need for pharmaceutical companies to invest in paediatric medicines. The costs associated with paediatric product development could result in poor or negative return on investment and so incentives have been proposed by the EU and US regulatory bodies. Additionally, some commonly used excipients may be unsuitable for use in children; and some dosage forms may be undesirable to the paediatric population.

Drug-induced and iatrogenic infiltrative lung disease

At present more than 350 drugs are known to cause injury of the lung parenchyma,upper and lower airways, pulmonary circulation, pleura, mediastinum, lymph nodes,and neuromuscular system. Infiltrative lung disease (ILD) is the most common pattern of drug-induced injury. This article, which is clinically oriented rather than drug oriented, reviews the patterns of ILD produced by therapeutic drugs and radiation therapy.

Cholinergic toxicity resulting from ocular instillation of echothiophate iodide eye drops

A patient developed a severe cholinergic syndrome from the use of echothiophate iodide ophthalmic drops, presented with profound muscle weakness and was initially given the diagnosis of myasthenia gravis. Red blood cell and serum cholinesterase levels were severely depressed and symptoms resolved spontaneously following discontinuation of the eye drops.

Beta-adrenergic function in aging. Basic mechanisms and clinical implications

Catecholamines have an important endocrine and neuroendocrine role in mediating a variety of autonomic functions. One consequence of normal aging, in particular in the cardiovascular system, is a decline in beta-adrenergic function associated with an alteration in responsiveness to beta-adrenergic therapy. The intrinsic ability for muscle contractility or relaxation is maintained with age and there appears to be an alteration in the process linking the receptor with the contractile or relaxation mechanisms. In rats, beta-adrenergic receptor density decreases with age in adipose tissues and most brain areas, is unchanged in lymphocytes, heart and lung, and increases in the liver. In humans, there are no receptor changes with age in either lymphocytes or brain. In contrast, the number of high-affinity receptors (or coupled receptors) decreases with age in most tissues. In addition, there is a decrease in membrane adenylate cyclase activity or cellular production of cyclic adenosine monophosphate (adenosine 3',5'-cyclic phosphate; cAMP). Plasma noradrenaline (norepinephrine) concentration increases with age. The reduced receptor number in some tissues (down-regulation), the reduced high-affinity receptors and the reduced hormone-stimulated adenylate cyclase activity with age suggests receptor desensitisation to increased plasma noradrenaline concentration. The inability of older animals to desensitise to beta-adrenergic agonists further supports this hypothesis. However, there is an additional post-receptor reduction in catalytic unit activity with age independent of desensitisation. Medications directed at the beta-adrenergic system are commonly used in the elderly. Many of the data on the impact of age on clinical responses are conflicting or unavailable. Concomitant disease, functional status, nutritional state and polypharmacy may play an even greater role than age. However, the available data can be used to guide the selection of therapy, anticipate side effects, and predict potential interactions with other medications and diseases.