A number of interaction checks are performed when a new medication is prescribed for a patient, if they are flagged as pregnant, or if their allergies or warnings are changed. It is possible to disable interaction checking via Prescribing Options.
Drug-Age Checking
When a new medication is prescribed, it is checked for suitability against the patient's age.
Drug-Age/Sex-at-Birth Checking
When a new medication is prescribed, it is checked for suitability against the patient's age and sex-at-birth.
Drug-Allergy Checking
When a new medication is prescribed, it is checked against the patient's allergy list, and warnings are given if there is an interaction. Clinical also checks a patient's current medications when a new allergy or history item is added for the patient. If either are found, a warning is displayed, with the option to Continue or Cancel the entry. Selecting Cancel cancels the new medication and returns you to the medication list.
Drug-Breast Feeding Checking
When a new medication is prescribed, a check is made to see if the patient is flagged as breast feeding (indicated by the associated check box on the Allergies/Warnings tab of the patient’s demographics).
Drug-Disease Checking
When a new medication is prescribed, Clinical checks for drug-disease interactions. The diseases that have been added to the patient's past medical history are compared to a hard-coded condition list. Clinical gives specific contraindications, precautions, and warning statements when any MDref-listed drug is prescribed, if the patient has any disease noted in the Product Information documents currently available.
It is possible to view the current list of drug-disease interactions
for a particular drug via MDref.
Within MDref, click 
to see the list of interactions checked against when that drug
is prescribed. This information is updated every time the MDref
drug database is updated.
Drug-Drug Checking
The new medication is checked against existing medications in the patient's record for any interactions. Interaction checking is carried out on the basis of generic names and generic grouping of the drugs in the database. Checks are also made to determine if the drug, or another drug in the same class, is already prescribed for the patient.
Prompts to warn you of drug-drug interactions only appear at the time a new drug is added to the patient's medication list. If you choose to prescribe the new item, you will not be prompted again upon printing a repeat prescription for either of the two items.
There are a number of drug-to-drug interaction types checked by the Clinical program:
The first is a simple reminder. This is given if a patient is prescribed a drug from the same group as a drug already on their current medication list. A warning window is displayed asking if you wish to continue prescribing the medication. A similar reminder is given whenever an antibiotic is prescribed to a patient on the Oral Contraceptive pill.
Interactions between drugs that are of more significance are divided into a number of categories. A warning message describing the general form of the interaction is displayed and the prescriber must choose whether to continue with the prescription of the new medication. For some interactions, the default option is to Proceed. This occurs where caution should be observed in using the two drugs simultaneously, for example a benzodiazepine with an antihistamine.
Interaction checking occurs where the addition of the new drug may require adjustment of the dose of a drug that is already prescribed, or where the dose of the new drug may need to be monitored because of a drug that is already being taken, for example adding PHENYTOIN and THEOPHYLLINE.
For more serious interactions, the default option is to cancel the prescription of the new drug. These are interactions where it is best not to use the two drugs together without careful consideration of the potential consequences, for example WARFARIN and ASPIRIN, or TERFENADINE and KETOCONAZOLE.
If you wish to see more information regarding the interaction
which has been flagged, click 
on the prompt
to open the full Prescribing Information sheet for the item being
prescribed.
As with allergy checking, it is almost always possible to override the default option. Ultimately the decision on whether to prescribe a particular combination of drugs is left up to the clinical judgment of the practitioner using the program.
As the new drug is checked against every drug on the patient's current list, it is possible to have multiple warnings. If you choose to continue at one warning, that does not stop the program from checking all items on the list, as there may be a more serious interaction with another medication on the list.
It is possible to view the current list of interactions for
any drug by looking it up in MDref. Once in MDref, click to see the list of interactions that is checked
for when that drug is prescribed. This information is updated
every time the MDref drug update is installed.
Drug-Gluten Checking
For Gluten warnings to appear, you need to record any of the following diseases in the patient's Past Medical History:
Gluten intolerance
Gluten enteropathy
Coeliac disease
Dermatitis herpetiformis
If a medication containing gluten is prescribed for a patient having any of the above items in their history, a warning is displayed giving details of the gluten interaction. The prescriber then has the choice of proceeding, canceling or viewing the Product Information for more information about the interaction.
Drug-Pregnancy Checking
Interactions between a drug and pregnancy are checked when:
A new medication is added - the patient's record is checked to determine if a current pregnancy is recorded.
An existing medication is re-prescribed i.e. re-printed via the CurrentRx tab of the patient's record.
A new pregnancy is recorded for the patient - their current medication list is checked. Likewise when a patient is flagged as pregnant, their current medications list is checked for interactions. If any medications are found which are known to interfere with the pregnancy, a warning window which includes the pregnancy code is displayed for each interacting drug. Also, for category X medications, you must confirm that you wish to prescribe/maintain the prescription by manually typing the word YES into the associated prompt window.
Drug-Spelling Checking
When a new medication is prescribed, a check is made against similarly-spelled medications. The user will be prompted to confirm their selection.
Drug-Sport Checking
When a new medication is prescribed, a check is made to see if the patient is flagged as an elite sports person (indicated by the associated check box on the Allergies/Warnings tab of the patient’s demographics).