- phenylephrine hydrochloride
GSL: General Sales Licence
This information is intended for use by health professionals
|Active Constituents||mg / 6g powder|
Directions for useEmpty contents of sachet into beaker. Half fill with very hot water. Stir well. Add cold water as necessary and sugar if desired.
Recommended Dose and Dosage Schedule
Adults (including elderly) and children aged 16 years and over:One sachet to be taken every four to six hours, as necessary. Do not exceed six sachets per 24 hours.Do not take continuously for more than 7 days without medical advice.Not to be given to children under 16 years, of age except on medical advice.
Special label warningsDo not take with other flu, cold or decongestant products. Do not take with any other paracetamol-containing products.Immediate medical advice should be sought in the event of an overdose, even if you feel well.
Special leaflet warningsImmediate medical advice should be sought in the event of an overdose, even if you feel well, because of the risk of delayed, serious liver damage.
|Monoamine oxidase inhibitors (including moclobemide)||Hypertensive interactions occur between sympathomimetic amines such as phenylephrine and monoamine oxidase inhibitors (see contraindications).|
|Sympathomimetic amines||Concomitant use of phenylephrine with other sympathomimetic amines can increase the risk of cardiovascular side effects.|
|Beta-blockers and other antihypertensives (including debrisoquine, guanethidine, reserpine, methyldopa)||Phenylephrine may reduce the efficacy of beta-blocking drugs and antihypertensive drugs. The risk of hypertension and other cardiovascular side effects may be increased.|
|Tricyclic antidepressants (e.g. amitriptyline)||May increase the risk of cardiovascular side effects with phenylephrine.|
|Ergot alkaloids||(ergotamine and methylsergide) increased risk of ergotism|
|Digoxin and cardiac glycosides||Increase the risk of irregular heartbeat or heart attack|
ParacetamolAdverse events from historical clinical trial data are both infrequent and from small patient exposure. Accordingly, events reported from extensive post-marketing experience at therapeutic/labelled dose and considered attributable are tabulated below by system class. Due to limited clinical trial data, the frequency of these adverse events is not known (cannot be estimated from available data), but post-marketing experience indicates that adverse reactions to paracetamol are rare and serious reactions are very rare.
|Body System||Undesirable effect|
|Blood and lymphatic system disorders||Thrombocytopenia Agranulocytosis These are not necessarily causally related to paracetamol|
|Immune system disorders||Anaphylaxis Cutaneous hypersensitivity reactions including skin rashes, angiodema and Stevens Johnson syndrome/toxic epidermal necrolysis|
|Respiratory, thoracic and mediastinal disorders||Bromchospasm *|
|Hepatobiliary disorders||Hepatic dysfunction|
PhenylephrineThe following adverse events have been observed in clinical trials with phenylephrine and may therefore represent the most commonly occurring adverse events.
|Body System||Undesirable effect|
|Psychiatric disorders||Nervousness, irritability, restlessness, and excitability|
|Nervous system disorders||Headache, dizziness, insomnia|
|Cardiac disorders||Increased blood pressure|
|Gastrointestinal disorders||Nausea, Vomiting.|
|Eye disorders||Mydriasis, acute angle closure glaucoma, most likely to occur in those with closed angle glaucoma|
|Cardiac disorders||Tachycardia, palpitations|
|Skin and subcutaneous disorders||Allergic reactions (e.g. rash, urticaria, allergic dermatitis). Hypersensitivity reactions including that cross-sensitivity may occur with other sympathomimetics|
|Renal and urinary disorders||Dysuria, urinary retention. This is most likely to occur in those with bladder outlet obstruction, such as prostatic hypertrophy.|
ParacetamolLiver damage is possible in adults who have taken 10g or more of paracetamol. Ingestion of 5g or more of paracetamol may lead to liver damage if the patient has risk factors (see below).
Risk factors:If the patient a, Is on long term treatment with carbamazepine, phenobarbitone, phenytoin, primidone, rifampicin, St John's Wort or other drugs that induce liver enzymes. Or b, Regularly consumes ethanol in excess of recommended amounts. Or c, Is likely to be glutathione deplete e.g. eating disorders, cystic fibrosis, HIV infection, starvation, cachexia.
Symptoms:Symptoms of paracetamol overdosage in the first 24 hours are pallor, nausea, vomiting, anorexia and abdominal pain. Liver damage may become apparent 12 to 48 hours after ingestion. Abnormalities of glucose metabolism and metabolic acidosis may occur. In severe poisoning, hepatic failure may progress to encephalopathy, haemorrhage, hypoglycaemia, cerebral oedema, and death. Acute renal failure with acute tubular necrosis, strongly suggested by loin pain, haematuria and proteinuria, may develop even in the absence of severe liver damage. Cardiac arrhythmias and pancreatitis have been reported.
Management:Immediate treatment is essential in the management of paracetamol overdose. Despite a lack of significant early symptoms, patients should be referred to hospital urgently for immediate medical attention. Symptoms may be limited to nausea or vomiting and may not reflect the severity of overdose or the risk of organ damage. Management should be in accordance with established treatment guidelines, see BNF overdose section.Treatment with activated charcoal should be considered if the overdose has been taken within 1 hour. Plasma paracetamol concentration should be measured at 4 hours or later after ingestion (earlier concentrations are unreliable). Treatment with N-acetylcysteine may be used up to 24 hours after ingestion of paracetamol, however, the maximum protective effect is obtained up to 8 hours post-ingestion. The effectiveness of the antidote declines sharply after this time. If required the patient should be given intravenous N-acetylcysteine, in line with the established dosage schedule. If vomiting is not a problem, oral methionine may be a suitable alternative for remote areas, outside hospital. Management of patients who present with serious hepatic dysfunction beyond 24h from ingestion should be discussed with the NPIS or a liver unit.
Symptoms and signsPhenylephrine overdosage is likely to result in effects similar to those listed under advserse reactions. Additional symptoms may include hypertension and possibly reflux bradycardia. In severe cases confusion, hallucinations, seizures and arrythmias may occur. However the amount required to produce serious phenylephrine toxicity would be greater than required to cause paracetamol-related toxicity.
TreatmentTreatment should be as clinically appropriate. Severe hypertension may need to be treated with an alpha blocking drug such as phentolamine.
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