When you are prescribed ADHD medication, it is important to be aware of how it may interact with other medications you are taking. Generally, ADHD medications are well tolerated alongside other treatments. However, certain medications can cause adverse interactions, so it is crucial to inform your clinician about all the medicines you are taking, including over-the-counter drugs and supplements. 

Some medications should not be taken with ADHD medication due to the potential for serious side effects. These are listed under the relevant ADHD medication, below: 

• Monoamine oxidase inhibitors (MAOIs) (e.g., phenelzine, tranylcypromine): Taking these together can lead to a hypertensive crisis (a dangerous increase in blood pressure). 

• Moclobemide: Similar to MAOIs, moclobemide should not be taken with methylphenidate due to the risk of a hypertensive crisis. 

• Clonidine: Serious adverse events have been reported when clonidine is combined with methylphenidate. 

• Monoamine oxidase inhibitors (MAOIs): As with methylphenidate, combining these medications can lead to a hypertensive crisis. 

• Moclobemide: Should not be taken with lisdexamfetamine or dexamfetamine due to the same hypertensive risk. 

• Monoamine oxidase inhibitors (MAOIs): Atomoxetine should not be taken with MAOIs for the same reason—there is a risk of a hypertensive crisis. 

• Increased risk of ventricular arrhythmias (irregular heartbeats) when taken with the following: 

  • Amiodarone 

  • Tricyclic antidepressants 

  • Antipsychotics 

  • Disopyramide 

  • Diuretics (causing hypokalaemia) 

  • Mefloquine 

  • Methadone 

  • Moxifloxacin 

  • Procainamide 

  • Sotalol 

• Medicines that lower blood pressure (e.g., antihypertensives): These may cause an excessive drop in blood pressure when taken with guanfacine. 

• Medicines for epilepsy (e.g., valproic acid): Can interact with guanfacine. 

• Sedatives: Sedatives, including benzodiazepines and barbiturates, can have a dangerous effect when taken with guanfacine. 

• Antipsychotics: Be cautious if you are also taking antipsychotics. 

• Enzyme inhibitors and inducers: Certain medications that affect the liver’s enzyme systems can alter the metabolism of guanfacine. 

• Inhibitors: 

  • Azoles (e.g., ketoconazole, fluconazole) 

  • Antibiotics (e.g., sulfonamides, metronidazole, ciprofloxacin) 

  • Other drugs like cimetidine, omeprazole, sodium valproate, and grapefruit juice. 

• Inducers: 

  • Anticonvulsants (e.g., phenytoin, carbamazepine, phenobarbitone) 

  • Steroids (e.g., dexamethasone, prednisolone) 

  • Rifampicin (antibiotic) 

  • Other substances like nicotine, alcohol, cigarette smoke, and St John’s Wort. 

• Consult your clinician: Before starting any new medication or supplement, check with your clinician or GP to ensure it is safe to take alongside your ADHD medication. 

• Regular reviews: As well as offering ad-hoc appointment options, we host annual reviews for all our clients and patients. We recommend that, whether you come to CARE ADHD or another provider for your ongoing medication services, you always review your medications regularly with the help of your clinician to monitor for any potential interactions. 

• Monitor for side effects: If you experience any new or unusual symptoms, inform your clinician or GP immediately. 

While ADHD medications are often compatible with other treatments, certain combinations can be harmful. It’s vital to inform your clinician of any other medications or supplements you are taking. This will help ensure that your ADHD medication is both safe and effective in supporting your treatment. 

To book an additional medication review, please make payment via this link and we’ll be in touch to arrange the appointment.