Glyceryl Trinitrate (IV)

Indication-specific starting rates and titration from §4.2 — Use in surgery (control of hypertension, or to produce hypotension during surgery): start 25 micrograms/min, increase by increments of 25 micrograms/min at 5-minute intervals until blood pressure is stabilised; 10-200 micrograms/min are usually sufficient during surgery, although up to 400 micrograms/min has been required in some cases. Perioperative myocardial ischaemia: start 15-20 micrograms/min, with subsequent increments of 10-15 micrograms/min until the required effect is obtained. Unresponsive congestive heart failure: start 20-25 micrograms/min; may be decreased to 10 micrograms/min, or increased in steps of 20-25 micrograms/min every 15-30 minutes until the desired effect is obtained. Unstable angina: initial 10 micrograms/min with increments of 10 micrograms/min at approximately 30-minute intervals according to the needs of the patient. Admixture example given in the SPC: to obtain 100 micrograms/mL, add 50 mL of glyceryl trinitrate solution (containing 50 mg) to 450 mL of infusion vehicle for a final volume of 500 mL; a dosage of 100 micrograms/min is then obtained by giving 60 mL of the admixture per hour. In case of dilution the product must be mixed under aseptic conditions immediately after opening; vials are single use only. Giving sets made of polyvinyl chloride (PVC) or polyurethane (PU) cause loss of active substance by adsorption — if used, the dose must be adjusted; polyethylene, polypropylene and PTFE have proven suitable. Avoid reducing systolic blood pressure below 90 mmHg. The solution contains glucose — take into account in diabetes mellitus. Tolerance and cross-tolerance to other nitro compounds has been described. Methaemoglobinaemia has been reported; methylene blue treatment is contraindicated in glucose-6-phosphate or methaemoglobin-reductase deficiency. Elderly: no evidence that a posology adjustment is required. Paediatric: safety and efficacy has not yet been established in children. Source is the UK SPC for 'Glyceryl Trinitrate 1 mg/ml solution for infusion' (eMC product 6296); §4.5 was truncated at source fetch, so the interaction list is partial and is drawn from §4.3 and §4.4. NOTE: the US label fetched as cross-check is nitroglycerin SUBLINGUAL tablets — a different route and regimen entirely; it was not used.