Adverse effects by incidence and severity Common * Bradyarrhythmia (low heart rate) * Hypotension (low blood pressure) * Palpitations * Tachyarrhythmia (high heart rate) * Apprehension * Restlessness * Confusion * Dizziness * Headache * Somnolence * Rash * Sweating * Thyroid suppression * Muscle twitch * Oliguria * Renal azotemia Unknown frequency * Nausea * Retching * Anxiety * Chest discomfort * Paraesthesial warmth * Abdominal pain * Orthostatic hypotension * ECG changes * Skin irritation * Flushing * Injection site erythema * Injection site streaking Serious * Ileus * Reduced platelet aggregation * Haemorrhage * Increased intracranial pressure * Metabolic acidosis * Methaemoglobinaemia * Cyanide poisoning * Thiocyanate toxicity Contraindications<unk>  should not be used for compensatory hypertension (e.g. due to an arteriovenous stent or coarctation of the aorta). It should not be used in patients with inadequate cerebral circulation or in patients who are near death. It should not be used in patients with vitamin B12 deficiency, anaemia, severe renal disease, or hypovolaemia. Patients with conditions associated with a higher cyanide/thiocyanate ratio (e.g. congenital (Leber's) optic atrophy, tobacco amblyopia) should only be treated with<unk>  with great caution. Its use in patients with acute congestive heart failure associated with reduced peripheral resistance is also not recommended. Its use in hepatically impaired individuals is also not recommended, as is its use in cases of pre-existing hypothyroidism. Its use in pregnant women is advised against, although the available evidence suggests it may be safe, provided maternal pH and cyanide levels are closely monitored. Some evidence suggests<unk>  use in critically ill children may be safe, even without monitoring of cyanide level. Interactions The only known drug interactions are pharmacodynamic in nature, that is it is possible for other antihypertensive drugs to reduce the threshold for dangerous hypotensive effects to be seen. Overdose Due to its cyanogenic nature, overdose may be particularly dangerous. Treatment of<unk>  overdose includes the following: * Discontinuing<unk>  administration * Buffering the cyanide by using<unk>  nitrite to convert haemoglobin to methaemoglobin as much as the patient can safely tolerate * Infusing<unk>  thiosulfate to convert the cyanide to thiocyanate. Haemodialysis is ineffective for removing cyanide from the body but it can be used to remove most of the thiocyanate produced from the above procedure. Toxicology The cyanide can be detoxified by reaction with a sulfur-donor such as thiosulfate, catalysed by the enzyme rhodanese. In the absence of sufficient thiosulfate, cyanide ions can quickly reach toxic levels. Hydroxocobalamin can be administered to reduce the risk of thiocyanate toxicity induced by<unk> . Species LD50 (mg/kg) for oral administration LD50 (mg/kg) for IV administration LD50 (mg/kg) for skin administration Mouse 43 8.4 ? Rat 300 11.2 >2000 Rabbit ? 2.8 ? Dog ? 5 ?
Sodium nitroprusside
Balsalazide
Adenosine
Ergotamine
Isoprenaline
Dobutamine
Nitroglycerin 
Labetalol