Wednesday, April 24, 2019

Therapeutic drug monitoring intro

To most fresh provisional registered pharmacists who entered therapeutic drug monitoring (in short, TDM), TDM is about

  • calculation using formula
  • withold or continue the drug based on drug level, and finally
  • recommendations of standard monitoring parameter.
Well, it sums up quite well in a way. However, to me, there is a few fundamental concepts that we should touch on.

First and foremost, we need to have an understanding of why we do TDM. I personally see the TDM playing three important roles: 
  • First, it is to ensure the narrow therapeutic window drug level is within therapeutic range. If the drug level is below or above the range, it will serve as a guide for dosage adjustment. However, the result should be interpreted in a clinical context. To illustrate, we would not adjust the dose of antiepileptic drug if the patient is seizure free despite has a drug level lower than therapeutic range.
  • to check patient compliance to a drug, for example when we do a random sampling of an antiepileptic.
  • to check for drug toxicity if suspected, for example paracetamol poisoning.
Every one of us is very different from each other, including how our body react to an administered drug. Scientifically speaking, there could be an interpatient variability in the dose-regimen relationship or what we termed as "pharmacokinetic difference”. When a patient is started on a narrow therapeutic window drug, the dosing will be based on population data. It is only after doing a TDM, we might be able to draw out a more precise estimation based on the individual patient profile. In real practice, the estimated value does not equivalent to the actual measured value. Hence, resampling of drug is unavoidable still.

In TDM, estimation using formula is very important still. I used to think that there is no need for me to guide you on calculation since you are just playing around the formula given. However, past experience taught me otherwise. If a wrong formula is being utilized, wrong estimation will be made and this will be followed by wrong recommendations, such as unnecessary resampling. Hence, an appreciation should be given to the TDM formulae, instead of blindly using them.

Friday, April 12, 2019

GINA 2019 is now available

This year, we saw another major change in the GINA strategy report in asthma management.

For safety reasons, GINA no longer recommends treatment with short-acting beta2-agonist (SABA) alone. Although SABA provides quick relief of symptoms, SABA-only treatment is associated with increased risk of exacerbation and lower lung function.

On the other hand, all adults and adolescents with asthma should receive inhaled corticosteroid (ICS)-containing controller treatment. These options now include:

  • (for mild asthma) as-needed low dose ICS-formoterol, or if not available, low dose ICS taken whenever SABA is taken, or
  • regular ICS or ICS-LABA every day, plus as-needed SABA or
  • maintenance and reliever treatment with ICS-formoterol, with the reliever being low-dose budesonide-formoterol or beclomethasone dipropionate-formoterol.

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Thursday, March 28, 2019

CP1 Medication History Assessment Form

When you embarked on the journey as a provisional registered pharmacist in Ministry of Health facilities, you will be introduced with 3 important CP forms in your ward rotation, namely:
  • CP1 Medication History Assessment Form
  • CP2 Pharmacotherapy Review
  • CP3 Clinical Pharmacy Report Form
These forms can be found in the Appendix VI, VIII and IX in this document.

Today, we will only discuss about CP1 form, which to me is the most significant of all the forms. The purpose of this form is very similar to the concept of medication reconciliation that I have learned in university year. When the patient is admitted to emergency department, the doctors do a quick history taking of patient including their medication. However, what studies have shown is that pharmacist-recorded medication histories result in higher accuracy and fewer medication errors.

First and foremost, why is there a need for us to take a complete medication history including their over-the-counter product and chronic medications? Ideally, CP1 form should be filled within the first 24 hours after patient admission. After completing the CP1 form, we should then compare the medications with the medications that patient is taking in ward and do active intervention when needed. This will eventually ensure a continuation of medications after patient admission to wards. Sometimes, with an effective medication reconciliation and patient interview, we would be able to identify treatment gaps, possible drug-related problems and intentional or non-intentional noncompliance. Certainly, we could also assess patient insulin injection technique or inhaler techniques during the same interview session.

Personally, I believe this medication history assessment form should be used at three stages to provide a thorough patient-centered care approach.
  • Initial admission
  • Transfer of patients to other wards (transition of care)
  • Patient discharge
In the transition of care, omission of drugs could occur. Hence, at these stages, clinical pharmacist should actively perform medication reconciliation to minimize the potential errors. On the other hand, at the time of patient discharging to home, clinical pharmacists should compare the discharge medication prescription with the initial medication history assessment form. By doing this, we can identify any medication changes that we should notify the patients and give a proper counseling for those newly started medications.


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