Only midwives who have completed the “Opioids and Benzodiazepines: Safe Prescribing for Midwives” course may independently prescribe controlled substances.
Lorazepam is a benzodiazepine, an anti-anxiety agent and sedative which binds to benzodiazepine receptors on the postsynaptic neuron at several sites within the central nervous system.
Indications and Clinical Use:
Midwives may only prescribe, order or administer Lorazepam on their own authority for 1) therapeutic rest in prodromal labour, 2) short-term management of excessive postpartum anxiety while the midwife is arranging for consultation with a physician for further diagnosis and ongoing treatment or 3) upon diagnosis of intrauterine fetal demise. Lorazepam may be used to promote therapeutic rest during prodromal labour; however, due to the long half-life of 12 hours, use of analgesia may be more appropriate over Lorazepam as a first choice. Lorazepam may be used during the early postpartum period, particularly where anxiety and/or insomnia due to anxiety or transient stress are factors and non-pharmacologic measures have been ineffective. Administration under any other circumstance must be on the order of a physician.
Hypersensitivity to benzodiazepines or to any component of the formulation. Lorazepam should not be taken in conjunction with alcohol or other sedating medications. Benzodiazepines should not be used in the presence of the following medical conditions: glaucoma, liver or kidney impairment, hyperkinesias, hypoalbuminaemia, myasthenia gravis, or any type of organic brain disorder. Benzodiazepines should not be given where there is a history of substance use or dependency. Benzodiazepines are not recommended in the first trimester of pregnancy because of the potential for congenital malformations. When these drugs are taken to treat anxiety disorders, information on the risks and alternate approaches to therapy should be offered.
Warnings and Precautions:
All practitioners caring for an individual taking a benzodiazepine should be aware that long-term use can result in dependency and withdrawal symptoms when the medication is discontinued. Prolonged doses of benzodiazepines during pregnancy and/or the postpartum period may cause physical dependence with resulting withdrawal symptoms in the neonate. Before prescribing, ordering or administering a benzodiazepine to a client with a depressive, chronic psychotic, phobic or obsessive behavioral disorder or potential suicidal tendencies, consultation with a physician is required.
While benzodiazepines may be prescribed for postpartum psychosis, these medications do enter breast milk and, if used during breastfeeding, midwives should watch for possible sedation, feeding difficulties and weight loss in the neonate. Hypoglycemia and respiratory problems in the neonate may occur following exposure late in pregnancy. Elimination of benzodiazepines in the neonate following in-utero exposure can be slow. Lorazepam is considered an intermediate acting benzodiazepine with a half-life of 12 hours for adults and 30 hours, with a range of 18-73 hours for neonates.
Benzodiazepines given near delivery could cause respiratory depression and hypoglycemia in neonates. Prolonged use in gestation may cause neonatal withdrawal
Benzodiazepines have been associated with anterograde amnesia; may impair physical or mental abilities; may cause hypotension; may cause hyperactive or aggressive behavior.
Use with caution in the presence of hepatic impairment, renal impairment, respiratory disease, substance use, alcohol use, personality disorders or depression.
When taking this medication one should not operate machinery or drive a vehicle.
Human Data Suggest Risk in the 1st and 3rd trimesters. One report found a significant association with fetal anal atresia. When used close to delivery, respiratory depression, hypotonia, lethargy and withdrawal symptoms have been reported. The long-term effects of in utero exposure on neurobehaviour, especially when exposure occurs in the latter half of pregnancy, have not been studied but are of concern.
Category L3 – Limited Human Data – Probably Compatible
Lorazepam is one of the preferred benzodiazepines in lactation, due to its shorter half-life and lack of an active metabolite. About 3% of the dose is known to enter breastmilk. If this medication is used in lactation the lowest effective dose should be given for the shortest possible period of time. The neonate should also be monitored for signs of sedation, such as not waking up to feed at regular intervals.
Benzodiazepines may cause drowsiness, blurred vision, dizziness and impaired concentration. Other potential side effects include lack of muscle coordination, nausea, constipation, visual disturbances, skin rash, and loss of bladder control. If breathing difficulties, fainting, rash or hypotension are experienced a physician should be contacted immediately.
Clinical judgement should be exercised as lorazepam does cross the placental barrier. Should labour progress more rapidly than anticipated, Flumazenil, a benzodiazepine receptor antagonist, may be required and should be readily available for administration. Immediately after administration physician consultation is required. (Please refer to the section on Flumazenil at the end of the benzodiazepine section.)
Dosage and Administration:
Usual dose: 0.5-2mg SL/PO BID or TID
Insomnia: 0.5-1mg SL/PO BID or TID
Anxiety: 0.5 – 2mg SL/PO BID or TID
In prodromal labour the dose may be repeated 12 hours later if needed and labour is not yet active. No more than two consecutive doses should be given when used in labour.
In treating postpartum anxiety, the dose may be given every 12 hours for no more than 3 days or a maximum of six doses. Once postpartum treatment is initiated, physician consultation must be arranged. The sublingual tablet will dissolve in approximately 20 seconds. Wait at least 2 minutes before swallowing to allow sufficient time for absorption.
Lorazepam may be prescribed in hospital or in the community. It does not require a controlled drugs and substances duplicate prescription pad. A prescription cannot exceed three days. No refills.
Onset of Action:
After sublingual use: 15-30 minutes
Peak action: 2 hours
Adult – 12 hours
Neonate – 30 hours, range 18-73 hours
Urine as metabolites