Check your answers on page 218https://doi.org/10.12968/jprp.2024.6.5.194
Benzodiazepines are commonly used medications that potentiate the effect of GABA to decrease neuronal excitability and activity. They can be used acutely to treat insomnia or control seizures, or in acute care settings as an intravenous sedation.
If patients have been sedated for prolonged periods, abrupt discontinuation is undesirable as withdrawal could be precipitated. However, there will also be situations in which patients will need to have intravenous access withdrawn before being fully weaned from an intravenous benzodiazepine, and in such cases it can be useful to convert a patient to an alternate agent while facilitating a wean.
The following case calculation considers a situation in which a 7.2 kg patient is on a midazolam infusion and there is an intention to convert a patient to oral diazepam.
QUESTION 1
If the patient has a syringe set up which contains 45 mg/50 ml of midazolam and is running at 1.5 ml/hour, what is the dose the patient is receiving in microgram/kg/hour?
The suggested threshold for considering an iv to oral benzodiazepine conversion with midazolam is 150 micrograms/kg/hour.
QUESTION 2
What rate of infusion will meet the threshold for converting for this patient?
QUESTION 3
From the value calculated in Question 2, project a total daily midazolam dose for this patient in milligrams.
The conversion of total daily dose for IV midazolam to oral diazepam involves multiplying the midazolam dose by 0.3 (Warrington et al, 2018).
QUESTION 4
What is the oral diazepam total daily dose that this patient is likely to need?
QUESTION 5
If the diazepam is going to be administered four times a day using 2 mg/5 ml solution, what volume should be administered for each dose?
The values obtained from this conversion can be seen as a starting point for conversion so that titration and weaning of effects based on clinical response can be implemented.