Not recommended
Alcohol
Lorazepam should not be used together with alcohol (enhanced sedative effects; impaired ability to drive/operate machinery)
Sodium oxybate
Avoid concomitant use (enhanced effects of sodium oxybate)
HIV-protease inhibitors
Avoid concomitant use (increased risk of prolonged sedation – see below for zidovudine
Take into account
Opioids
The concomitant use of sedative medicines such as benzodiazepines or related drugs such as lorazepam with opioids increases the risk of sedation, respiratory depression, coma and death because of additive CNS depressant effect. The dosage and duration of concomitant use should be limited (see section 4.4).
Centrally acting drugs
Enhancement of the central depressive effect may occur if lorazepam is combined with drugs such as neuroleptics, antipsychotics, tranquillisers, antidepressants, hypnotics, analgesics, anaesthetics, barbiturates and sedative antihistamines. The elderly may require special supervision.
Anti-epileptic drugs
Pharmacokinetic studies on potential interactions between benzodiazepines and antiepileptic drugs have produced conflicting results. Both depression and elevation of drug levels, as well as no change have been reported.
Phenobarbital taken concomitantly may result in an additive CNS effect. Special care should be taken in adjusting the dose in the initial stages of treatment.
Side effects may be more evident with hydantoins or barbiturates
Valproate may inhibit the glucuronidation of lorazepam (increased serum levels: increased risk of drowsiness)
Narcotic analgesics
Enhancement of the euphoria may lead to increased psychological dependence
Clozapine
Reports of marked sedation, excessive salivation, hypotension, ataxia, delirium and respiratory arrest when given concurrently with lorazepam.
Muscle Relaxants
When taken with muscle relaxants, the overall muscle-relaxing effect may be increased (accumulative) therefore caution is advised, especially in elderly patients and at higher doses (risk of falling, see Section 4.4)
Other drugs enhancing the sedative effect of diazepam
Cisapride, lofexidine, nabilone, disulfiram and the muscle relaxants – baclofen and tizanidine
Compounds that affect hepatic enzymes (particularly cyctochrome P450)
• Inhibitors (e.g. cimetidine, isoniazid; erythyromycin; omeprazole; esomeprazole) reduce clearance and may potentiate the action of benzodiazepines. Itraconazole, ketoconazole and to a lesser extent fluconazole and voriconazole are potent inhibitors of the cytochrome P450 isoenzyme CYP3A4 and may increase plasma levels of benzodiazepines. The effects of benzodiazepines may be increased and prolonged by concomitant use. A dose reduction of the benzodiazepine may be required.
• Inducers (e.g. rifampicin) may increase clearance of benzodiazepines
Antihypertensives, vasodilators and diuretics: Enhanced hypotensive effect with ACE-inhibitors, alpha-blockers, angiotensin-II receptor antagonists, calcium channel blockers, adrenergic neurone blockers, beta-blockers, moxonidine, nitrates, hydralazine, minoxidil, sodium nitroprusside and diuretics
Enhanced sedative effect with alpha-blockers or moxonidine.
Dopaminergics
Possible antagonism of the effect of levodopa
Antacids
Concurrent use may delay absorption of lorazepam
Zidovudine
Increased zidovudine clearance by lorazepam
Oestrogen-containing contraceptives
Possible inhibition of hepatic metabolism of lorazepam
Theophylline/aminophylline
Increases metabolism of lorazepam which possibly reduces the effect
Caffeine
Concurrent use may result in reduced sedative and anxiolytic effects of lorazepam.
Grapefruit juice
Inhibition of CYP3A4 may increase the plasma concentration of lorazepam (possible increased sedation and amnesia). This interaction may be of little significance in healthy individuals, but it is not clear if other factors such as old age or liver cirrhosis increase the risk of adverse events with concurrent use.
Drug dependence, tolerance and potential for abuse
Drug addiction comprises behavioural, cognitive and physiological phenomena that may include a strong desire to take the drug, difficulties in controlling drug use and possible tolerance or physical dependence. Physical dependence is a state that develops as a result of physiological adaptation in response to repeated drug use, which manifests as withdrawal signs and symptoms after abrupt discontinuation or a significant dose reduction of a drug. Addiction and dependence are related but distinct presentations and in discussing these themes, terminology that apportion blame to the individual should be avoided.
For all patients, prolonged use of this product may lead to drug dependence and addiction but can occur with short-term use at recommended therapeutic doses. The risks are increased in individuals with current or past history of substance misuse disorder (including alcohol misuse) or mental health disorder (e.g., major depression).
Additional support and monitoring may be necessary when prescribing for patients at risk of drug misuse.
A comprehensive patient history should be taken to document concomitant medications, including over-the-counter medicines and medicines obtained on-line, and past and present medical and psychiatric conditions.
Patients may find that treatment is less effective with chronic use and express a need to increase the dose to obtain the same level of symptom control as initially experienced. Patients may also supplement their treatment with additional medications to achieve the same effect. These could be signs that the patient is developing tolerance. The risks of developing tolerance should be explained to the patient.
Overuse or misuse may result in overdose and/or death. It is important that patients only use medicines that are prescribed for them at the dose they have been prescribed and do not give this medicine to anyone else.
Patients should be closely monitored for signs of misuse, abuse, or addiction.
The clinical need for treatment with lorazepam should be reviewed regularly, with frequent assessments of patients being undertaken during the course of their treatment.
Drug withdrawal syndrome
Prior to starting treatment with lorazepam, a discussion should be held with patients to explain the risk of dependence, addiction, and drug withdrawal syndrome. A withdrawal strategy for ending treatment with lorazepam should also be put in place with the patient before starting treatment (there may be exceptions to this in specific clinical situations such as symptom management in end of the life palliative care, and for use in epilepsy).
Drug withdrawal syndrome may occur upon abrupt cessation of therapy or dose reduction. When a patient no longer requires therapy, it is advisable to taper the dose gradually to minimise symptoms of withdrawal. Tapering from a high dose may take in excess of weeks or months. Patients should be informed of this when the medication is first prescribed.
The reduction schedule for a patient should be tailored to the individual and should be modified to allow intolerable withdrawal symptoms to improve before making the next reduction. If using a published withdrawal schedule, apply it flexibly to accommodate the person's preferences, changes to their circumstances and the response to dose reductions.
Suggest a slow stepwise rate of reduction proportionate to the existing dose, so that decrements become smaller as the dose is lowered, unless clinical risk is such that rapid withdrawal is needed.
If a patient develops withdrawal reactions, consider pausing the taper or increasing the dosage to the previous tapered dosage level.
If women take this drug during pregnancy, there is a risk that their newborn infants will experience neonatal withdrawal syndrome