Pharmacovigilance Newsletter #4

Dear fellow healthcare professional,

Thank you for the warm response to the newsletters. Many thanks to those persons who have been submitting adverse drug reaction reports . Please continue to do this as these reports will help us to, among other things, determine the prevalence of adverse drug reactions (ADRs)  in our Jamaican population. The data collected is submitted to the Ministry of Health which in turn inserts the information into VIGIFLOW, the WHO’s  database of ADRs from around the world.

Let’s look at a few definitions-
Pharmacovigilance may be defined as the science of collecting, monitoring, researching, assessing, & evaluating current drug safety information from healthcare providers, with the aim of early identification of drug safety problems, their quantitative & qualitative characterization & prevention of harm to patients. An important goal is effective & open communication of safety information & supporting health education.
An adverse event (AE) may be defined as any unfavourable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.
AEs are unintended “ bad things” that occur when taking a drug. They may or may not be due the drug itself, the formulation, excipients , packaging , contaminants , manufacturing problems , the underlying disease or some other unknown cause or causes. And so an adverse event does not imply that the drug itself caused the “bad thing” to happen.  I am sure many of you have  had patients who complain of “low feelings “ when taking some medications and like me you have wondered “ What is happening here ? “ I would probably label some of those “ low feelings” as adverse events!
An adverse drug reaction is an adverse event in which there is a reasonable relationship between the drug and the adverse event.
An ADR may be defined as an unintended response, occurring at doses used in humans. They are defined as any noxious unintended and undesired effects of a drug that occur at doses used for prevention, diagnosis or treatment (WHO 1996). These reactions may predict hazards for future administration or warrant prevention or specific treatment, alteration of the dosage regimen or withdrawal
In summary an adverse drug reaction is harm directly caused by the drug at normal doses, during normal use.
 ADRs are an important cause of iatrogenic disease.
Although ADRs have several classifications, most include 2 basic types : predictable and unpredictable. Predictable or type A reactions account for about 80% of all ADRs. They occur when the normal effects of drugs are exaggerated to the point of being undesirable. They are dose dependent and related to the pharmacological action of the drug. Examples include
 Low blood pressure with anti-hypertensives
 Respiratory depression with opioids
 Hypoglycaemia with insulin
 Sedation with antihistamines
Unpredicatble or Type B reactions are
unpredictable, uncommon and  usually not related to pharmacological actions of drug. Unlike Type A reactions, they are not dose-dependent.
 Examples include
 anaphylaxis with penicillin administration
 tinnitus with the use of Aspirin

Our second workshop
“Pharmacovigilance, ensuring the safe use of medicines: The role of healthcare professionals in adverse drug reaction reporting “
will be held on Sunday April 25, 2010. This three hour workshop will consist of lectures and a hands on session in completing the “Pharmwatch” form used by the Ministry of Health to collect adverse drug reaction reports. You will soon be informed of details.

Remember you don’t have to be sure, just be suspicious. We all have a role to play in making drugs safe to use.
Best regards,
Dr. Jacqueline E. Campbell