Formulary
Acetylcysteine: Indications, Dosing, Side Effects and Interactions
Acetylcysteine clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 6 min read
Acetylcysteine: Indications, Dosing, Side Effects and Interactions
Acetylcysteine clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Tear deficiency,Impaired or abnormal mucus production**
- **Adult** (To The Eye): Apply 3-4 times a day.
**Paracetamol overdose [12-hour SNAP regimen]**
- **Child** (By Intravenous Infusion): (body-weight 40 kg and above) 100 mg/kg over 2 hours, dose to be administered in 200 mL glucose 5% or sodium chloride 0.9%, then 200 mg/kg over 10 hours, dose to be administered in 1 litre glucose 5% or sodium chloride 0.9%, and started immediately after completion of first infusion.
- **Adult** (By Intravenous Infusion): (body-weight 40 kg and above) 100 mg/kg over 2 hours, dose to be administered in 200 mL glucose 5% or sodium chloride 0.9%, then 200 mg/kg over 10 hours, dose to be administered in 1 litre glucose 5% or sodium chloride 0.9%, and started immediately after completion of first infusion.
**Paracetamol overdose [21-hour regimen]**
- **Child** (By Intravenous Infusion): (body-weight 40 kg and above) 150 mg/kg over 1 hour, dose to be administered in 200 mL glucose 5% or sodium chloride 0.9%, then 50 mg/kg over 4 hours, dose to be administered in 500 mL glucose 5% or sodium chloride 0.9%, and started immediately after completion of first infusion, then 100 mg/kg over 16 hours, dose to be administered in 1 litre glucose 5% or sodium chloride 0.9%, and started immediately after completion of second infusion.
- **Adult** (By Intravenous Infusion): (body-weight 40 kg and above) 150 mg/kg over 1 hour, dose to be administered in 200 mL glucose 5% or sodium chloride 0.9%, then 50 mg/kg over 4 hours, dose to be administered in 500 mL glucose 5% or sodium chloride 0.9%, and started immediately after completion of first infusion, then 100 mg/kg over 16 hours, dose to be administered in 1 litre glucose 5% or sodium chloride 0.9%, and started immediately after completion of second infusion.
**Reduction of sputum viscosity**
- **Adult** (By Mouth): 600 mg once daily.
**Tear deficiency, Impaired or abnormal mucus production for acetylcysteine**
- **Child** (To the eye): Apply 3-4 times a day.
**Paracetamol overdose [12-hour SNAP regimen] for acetylcysteine**
- **Neonate** (By intravenous infusion): 100 mg/kg over 2 hours, dose to be administered as a 50 mg/mL solution in glucose 5% or sodium chloride 0.9%, then 200 mg/kg over 10 hours, dose to be administered as a 10 mg/mL solution in glucose 5% or sodium chloride 0.9%, and started immediately after completion of first infusion.
- **Child (body-weight up to 40 kg)** (By intravenous infusion): 100 mg/kg over 2 hours, dose to be administered as a 50 mg/mL solution in glucose 5% or sodium chloride 0.9%, then 200 mg/kg over 10 hours, dose to be administered as a 10 mg/mL solution in glucose 5% or sodium chloride 0.9%, and started immediately after completion of first infusion.
- **Child (body-weight 40 kg and above)** (By intravenous infusion): 100 mg/kg over 2 hours, dose to be administered in 200 mL glucose 5% or sodium chloride 0.9%, then 200 mg/kg over 10 hours, dose to be administered in 1 litre glucose 5% or sodium chloride 0.9%, and started immediately after completion of first infusion.
**Paracetamol overdose [21-hour regimen] for acetylcysteine**
- **Neonate** (By intravenous infusion): 150 mg/kg over 1 hour, dose to be administered as a 50 mg/mL solution in glucose 5% or sodium chloride 0.9%, then 50 mg/kg over 4 hours, dose to be administered as a 6.25 mg/mL solution in glucose 5% or sodium chloride 0.9%, and started immediately after completion of first infusion, then 100 mg/kg over 16 hours, dose to be administered as a 6.25 mg/mL solution in glucose 5% or sodium chloride 0.9%, and started immediately after completion of second infusion.
- **Child (body-weight up to 40 kg)** (By intravenous infusion): 150 mg/kg over 1 hour, dose to be administered as a 50 mg/mL solution in glucose 5% or sodium chloride 0.9%, then 50 mg/kg over 4 hours, dose to be administered as a 6.25 mg/mL solution in glucose 5% or sodium chloride 0.9%, and started immediately after completion of first infusion, then 100 mg/kg over 16 hours, dose to be administered as a 6.25 mg/mL solution in glucose 5% or sodium chloride 0.9%, and started immediately after completion of second infusion.
- **Child (body-weight 40 kg and above)** (By intravenous infusion): 150 mg/kg over 1 hour, dose to be administered in 200 mL glucose 5% or sodium chloride 0.9%, then 50 mg/kg over 4 hours, dose to be administered in 500 mL glucose 5% or sodium chloride 0.9%, and started immediately after completion of first infusion, then 100 mg/kg over 16 hours, dose to be administered in 1 litre glucose 5% or sodium chloride 0.9%, and started immediately after completion of second infusion.
**Meconium ileus for acetylcysteine**
- **Neonate** (By mouth): 200-400 mg up to 3 times a day if required.
**Treatment of distal intestinal obstructive syndrome for acetylcysteine**
- **Child 1 month-1 year** (By mouth): 0.4-3 g as a single dose.
- **Child 2-6 years** (By mouth): 2-3 g as a single dose.
- **Child 7-17 years** (By mouth): 4-6 g as a single dose.
**Prevention of distal intestinal obstruction syndrome for acetylcysteine**
- **Child 1 month-1 year** (By mouth): 100-200 mg 3 times a day.
- **Child 2-11 years** (By mouth): 200 mg 3 times a day.
- **Child 12-17 years** (By mouth): 200-400 mg 3 times a day.
Cautions
With intravenous use Asthma; atopy; may slightly increase INR; may slightly increase prothrombin time With oral use Asthma; history of peptic ulceration
Side effects
With oral use Diarrhoea (in adults); fever (in adults); gastrointestinal discomfort (in adults); headache (in adults); hypotension (in adults); nausea (in adults); stomatitis (in adults); tinnitus (in adults); vomiting (in adults) Rare or very rare With oral use Haemorrhage (in adults) Frequency not known When used by eye (topical) Eye discomfort; eye redness With oral use Face oedema (in adults) With parenteral use Acidosis; anaphylactoid reaction; angioedema; anxiety; arrhythmias; cardiac arrest; chest discomfort; cough; cyanosis; eye pain; eye swelling; generalised seizure; hyperhidrosis; hypertension; hypotension; joint disorders; malaise; nausea; pain facial; respiratory disorders; skin reactions; syncope; thrombocytopenia; vasodilation; vision blurred; vomiting Side-effects, further information Anaphylactoid reactions (with intravenous use) can be managed by suspending treatment and initiating appropriate management. Treatment may then be restarted at lower rate.
Interactions
**Severe interactions:**
- Concurrent use of nitroglycerin and acetylcysteine causes significant hypotension and leads to temporal artery dilation with possible onset of headache.
- If concurrent use of nitroglycerin and acetylcysteine is required, patients should be monitored and warned for hypotension that can be severe and accompanied by a headache.
**Other interactions (6):**
- Drug Interactions Antitussive drugs and acetylcysteine should not be administered concomitantly because reducing the cough reflex may lead to a build-up of bronchial secretions.
- Activated charcoal may reduce the effect of acetylcysteine.
- It is advisable not to mix Acetylcysteine 200 mg Powder for Oral Solution with other medicinal products.
- In vitro tests have shown that when cephalosporin antibiotics and acetylcysteine are mixed, there is a degree of antibiotic inactivation.
- It is precautionary to advise the administration of oral antibiotics at least two hours before or after acetylcysteine.
- Concomitant use of acetylcysteine and carbamazepine may result in sub-therapeutic carbamazepine levels.
Pregnancy
With intravenous use: TOXBASE advises that the toxic dose of paracetamol ingested should be calculated using the patient's pre-pregnancy body-weight and the acetylcysteine dose (for both regimens) should be calculated using the patient's actual pregnant body-weight.
Medicinal forms
Tablet,Tablet,Solution,Drops
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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