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The introduction of new disease-modifying therapies (DMTs) for remitting-relapsing multiple sclerosis (RRMS) has considerably transformed the landscape of therapeutic opportunities for this chronic disabling disease. Unlike injectable drugs, oral DMTs promote patient satisfaction and increase therapeutic adherence.This article reviews the salient features about the mode of action, efficacy, safety, and tolerability profile of approved oral DMTs in RRMS, and reviews their place in clinical algorithms in the Middle East and North Africa (MENA) region. A systematic review was conducted using a comprehensive search of MEDLINE, PubMed, Cochrane Database of Systematic Reviews (period January 1, 1995-January 31, 2018). Additional searches of the American Academy of Neurology and European Committee for Treatment and Research in Multiple Sclerosis abstracts from 2012-2017 were performed, in addition to searches of the Food and Drug Administration and European Medicines Agency websites, to obtain relevant safety information on these DMTs.Four oral DMTs: fingolimod, teriflunomide, dimethyl fumarate, and cladribine have been approved by the regulatory agencies. Based on the number needed to treat (NNT), the potential role of these DMTs in the management of active and highly active or rapidly evolving RRMS is assessed. Finally, the place of the oral DMTs in clinical algorithms in the MENA region is reviewed.

Objective: The aim of this hospital-based study is to get an insight into the efficacy and tolerability of antiepileptic drugs (AED) in Omani epileptic patients. Patients and methods: All Omani patients (aged 14 years and above) suffering from epileptic seizures for at least 2 years and followed-up by board-certified neurologists in Sultan Qaboos University Hospital (SQUH) were evaluated. The treatment retention rate since first visit at SQUH and over the last 2 years was used as primary efficacy measure of AED therapy. Change in seizure-frequency and side effect profiles were also assessed. Results: In this population of 203 confirmed epileptic patients, generalized tonic-clonic (40%) and partial seizures (39%) were most commonly observed, idiopathic/cryptogenic origin (81%) being the most frequent encountered origin. Sixty one percent of the patients were controlled with an AED in monotherapy and overall 34% of patients could be successfully maintained on monotherapy during the whole follow-up period at SQUH (median 6 years). The treatment retention rates for carbamazepine (CBZ) at a daily dose of 400–600 mg, sodium valproate (VPA) at a daily dose of 500–1000 mg, and phenytoin (PHT) at a daily dose of 300 mg, in monotherapy over the total follow-up period was 51, 50, and 21%, respectively. In contrast, over the last 2 years these rates were highest for VPA (91%) followed by CBZ (83%) and PHT (73%). Adverse drug reactions were recorded in 67% of patients, and were most commonly encountered with VPA. Conclusions: Despite a higher adverse effect profile for VPA, long-term treatment with CBZ and VPA appeared to be equally effective in terms of treatment retention rates and seizure control. © 2005 Elsevier B.V. All rights reserved.

Apomorphine, a short-acting dopamine D1 and D2 receptor agonist, was the first dopamine receptor agonist used to treat Parkinson's disease. Subcutaneous apomorphine is currently used for the management of sudden, unexpected and refractory levodopa-induced 'off' states in fluctuating Parkinson's disease either as intermittent rescue injections or continuous infusions. Other indications include the challenge test for determining the dopaminergic responsiveness and finding the appropriate dose of the drug in intermittent subcutaneous administration. Except for a rapid on- and offset of the antiparkinsonian response with subcutaneous apomorphine, the magnitude and pattern of the motor response to single dose of subcutaneously administered apomorphine is qualitatively comparable to that of oral levodopa. Seventy-five percent of patients achieve a clinically significant improvement with a dose of apomorphine 4mg. The efficacy of intermittent subcutaneous apomorphine injections as an add-on to levodopa therapy in advanced Parkinson's disease was explored in one short-term, randomised, double-blind, placebo-controlled trial, one short-term and six long-term, open-label, uncontrolled studies, including a total of 195 patients. These studies provide evidence that this mode of administration was successful in aborting 'off' periods and improving Parkinson's disease motor scores, but tended to increase dyskinesias. No levodopa-sparing effect was observed. Eleven long-term, open-label, uncontrolled studies, including a total of 233 patients evaluated the efficacy of continuous subcutaneous apomorphine infusions in monotherapy or as an add-on to levodopa therapy in advanced Parkinson's disease. These studies proved that subcutaneous apomorphine infusions are successful in aborting 'off' periods, reducing dyskinesias and improving Parkinson's disease motor scores with the added benefit of a substantial levodopa-sparing effect. The apomorphine challenge test has at least 80% overall predictive ability to clinically diagnose Parkinson's disease across the different stages of the disease and parkinsonian syndromes. Similarly, those data also indicate that the apomorphine challenge test has a >80% ability to predict dopaminergic responsiveness across all stages of Parkinson's disease. Adverse events are usually mild and consist predominantly of cutaneous reactions and neuropsychiatric adverse effects. The incidence of adverse effects is higher in patients receiving continuous infusion than in those receiving intermittent pulsatile administration. Based on the results of these studies it is recommended that subcutaneous apomorphine either as intermittent injections or continuous infusions should be offered to any suitable Parkinson's disease patient who has difficulties in his/her management with conventional therapy. Low-dose levodopa therapy in combination with waking-day hours subcutaneous apomorphine infusion would probably be the most efficient treatment. Continuous subcutaneous apomorphine infusions should be evaluated before more invasive measures or neurosurgical interventions are contemplated.

Remifentanil is an opioid analgesic frequently used in intensive care patients because of its rapid onset of action, potency, and ultra-short duration. If an excessive dose is given, it leads to rapid, short lasting, potentially life-threatening side effects such as apnea, bradycadia, hypotension, and rigidity, following rapid peak serum levels. We report a 36-year-old woman developing apnea with bradycardia and hypotension, following an infusion in the central venous catheter lumen that had been used for remifentanil till tracheal extubation. The patient was immediately ventilated with bag-valve-mask and improved within 8 minutes. She became fully awake, heart rate and blood pressure returned to normal, and oxygen saturation improved to 100%. Acute care physicians, intensivists, anesthesiologists, and critical care nurses should be aware of this clinical problem in order prevent it as much as possible and to initiate immediate resuscitative measures.

Case Report: A 21-year-old man who had sniffed toluene since the age of 13 presented with a 4-year history of progressive cerebellar dysfunction and visual deterioration. The patient's condition did not improve despite 5 months of abstinence. Magnetic resonance imaging revealed cerebral atrophy and hypointensity signals in the white matter and bilaterally in the globus pallidus, thalamus, red nucleus, and substantia nigra. Amantadine hydrochloride therapy (100 mg/d, then 200 mg/d) resulted in dramatic improvement of his cerebellar and visual symptoms.

A 42-year-old pregnant woman (26 weeks of gestation, G(4)P(0+3)) presented at the emergency department with a two-hour history of dizziness, blurred vision and repeated vomiting. These symptoms started during the use of an undiluted insecticide liquid (diazinon 60 EC) while cleaning a small non-aired bathroom. After clinical and laboratory confirmation for organophosphate poisoning (plasma pseudocholinesterase levels 161 U/l), treatment with atropine and pralidoxime was started. She recovered within 7 days and delivered a healthy baby 12 weeks later (Apgar score 9 and 10) by elective cesarean section. The child showed no signs or symptoms of organophospate, atropine or pralidoxime exposure.

Objectives: To describe the pharmaceutical use, health care resource utilisation patterns, and annual direct medical cost of epilepsy as well as determining the impact of various demographic and clinical characteristics on total costs of epilepsy in Oman. Methods: Medical and pharmacy data were collected for 6 months on all patients aged ≥13 years attending the Sultan Qaboos University Hospital. Unit pharmacy and medical costs were retrieved for each patient, and multiple linear regression was utilised to analyse the impact of various demographic and clinical characteristics on total cost. Results: A total of 486 patients were seen over the study period. Annual direct medical costs of epilepsy amounted to US$1426. In-patient care, the antiepileptic drug (AED) lamotrigine and specialist visits, respectively, were the first, second and third most significant predictors of total cost. Age was associated positively, and was the most significant predictor of total costs among demographic and clinical parameters. Conclusions: This analysis, the first economic study of epilepsy in Oman, could assist in health care allocation of scarce resources and in pharmacoeconomic analysis of AEDs. Besides in-patient admission, our findings demonstrate that the newer drugs are significant predictors of total cost, and hence any incremental benefits derived from them must be rigorously assessed for their cost-effectiveness.

Summary Purpose: To get an insight into the type and aetiology of epileptic seizures; to describe the drug utilization pattern of anti-epileptic drugs (AEDs) for the treatment of various forms of epileptic seizures in this tertiary referral centre in Oman; and to compare our drug utilization pattern with that from other countries. In addition, the tolerability of AEDs and the use of therapeutic drug monitoring (TDM) were evaluated. Methods: In a 6-month study, all epileptic patients aged 14 and above who were prescribed an AED were considered for analysis. Demographic data, type and aetiology of epileptic seizures, AED data, tests performed and adverse drug reaction (ADR) data were collected. Results: A total of 1039 prescriptions originated from 488 epileptic patients. The age ranged from 14 to 77 years (median, 24 years). Generalized tonic–clonic seizures (51%) of idiopathic/cryptogenic origin (83%) were the most common type and aetiology of epileptic seizures, respectively. An average of 1·34 AEDs per patient was prescribed with 78% of patients being on monotherapy. Sodium valproate (49%) was the most frequently prescribed AED, followed by carbamazepine (44%), phenytoin (12%) and lamotrigine (11%). Ten patients suffered an ADR and phenobarbital followed by carbamazepine were most commonly the subject of TDM. Conclusions: Unlike the results in most other studies, generalized seizures represented the majority of epileptic seizures. The selection of the AEDs corresponded well with their known efficacy profiles for specific epileptic seizure types. Monotherapy was the type of therapy most frequently used, and sodium valproate and carbamazepine were the most commonly used AEDs.

Current research in Parkinson’s disease (PD) focuses on symptomatic therapy and neuroprotective interventions. Drugs that have been used for symptomatic therapy are levodopa, usually combined with a peripheral decarboxylase inhibitor, synthetic dopamine receptor agonists, centrally-acting antimuscarinic drugs, amantadine, monoamine oxidase-B (MAO-B) inhibitors and catechol-O-methyltransferase (COMT) inhibitors. Drugs for which there is at least some evidence for neuroprotective effect are certain dopamine agonists, amantadine and MAO-B inhibitors (selegiline). Levodopa remains the most effective drug for the treatment of PD. Several factors contribute to the complex clinical pharmacokinetics of levodopa: erratic absorption, short half-life, peripheral O-methylation and facilitated transport across the blood-brain barrier. In patients with response fluctuations to levodopa, the concentration-effect curve becomes steeper and shifts to the right compared with patients with stable response. Pharmacokinetic-pharmacodynamic modelling can affect decisions regarding therapeutic strategies. The dopamine agonists include ergot derivatives (bromocriptine, pergolide, lisuride and cabergoline), non-ergoline derivatives (pramipexole, ropinirole and piribedil) and apomorphine. Most dopamine agonists have their specific pharmacological profile. They are used in monotherapy and as an adjunct to levodopa in early and advanced PD. Few pharmacokinetic and pharmacodynamic data are available regarding centrally acting antimuscarinic drugs. They are characterised by rapid absorption after oral intake, large volume of distribution and low clearance relative to hepatic blood flow, with extensive metabolism. The mechanism of action of amantadine remains elusive. It is well absorbed and widely distributed. Since elimination is primarily by renal clearance, accumulation of the drug can occur in patients with renal dysfunction and dosage reduction must be envisaged. The COMT inhibitors entacapone and tolcapone dose-dependently inhibit the formation of the major metabolite of levodopa, 3-O-methyldopa, and improve the bioavailability and reduce the clearance of levodopa without significantly affecting its absorption. They are useful adjuncts to levodopa in patients with end-of-dose fluctuations. The MAO-B inhibitor selegiline may have a dual effect: reducing the catabolism of dopamine and limiting the formation of neurotoxic free radicals. The pharmacokinetics of selegiline are highly variable; it has low bioavailability and large volume of distribution. The oral clearance is many-fold higher than the hepatic blood flow and the drug is extensively metabolised into several metabolites, some of them being active. Despite the introduction of several new drugs to the antiparkinsonian armamentarium, no single best treatment exists for an individual patient with PD. Particularly in the advanced stage of the disease, treatment should be individually tailored.

Sterile neurogenic inflammation within cephalic tissue, involving vasodilation and plasma protein extravasation, has been proposed as a pathophysiological mechanism in acute migraine. The action of 5-hydroxytryptamine (5-HT1B/1D) agonists--so-called triptans--on receptors located in meningeal arteries (5-HT1B) and trigeminovascular fiber endings (5-HT1D) has an inhibitory effect on this neurogenic inflammation. Recently, a series of second-generation 5-HT1B/1D agonists (almotriptan, eletriptan, frovatriptan, naratriptan, rizatriptan, and zolmitriptan) have been developed and are reviewed in this article. Their in vitro pharmacological properties, pharmacokinetics, clinical efficacy, drug interactions, and adverse effects are evaluated and compared to the golden standard in the treatment of acute migraine, sumatriptan.

We read with interest the article by Miyagi et al 1 and comment on the medical treatment of toluene induced tremor. Microdialysis experiments in rats have shown that inhalation of toluene increases extracellular γ-aminobutyric acid (GABA) concentrations within the cerebellar cortex2 which probably explains why GABA agonists including benzodiazepines (for example, clonazepam) are not very effective in toluene induced tremor and ataxia. Rat experiments also showed a 50% reduction in …