How to use the drug database

Some useful points

  • The drug database has a search engine. You can check the safety classification of a drug by simply typing the drug name (or the first part of it).
  • Trade names or generic drug names can be used. The different national versions of the drug database are adapted to The National Drug Catalogue or pharmacopoeia in each country.
  • The search engine uses automatic wild card searching. A search is performed although only a part of the drug name is typed in. This can be the first, middle, or last part of the drug name. It is recommended to use at least 5 characters of the first part of the generic name or trade name.

Two modes of function

The Drug Database for Acute Porphyria can be used in two modes:

  1. To search for information about the general safety of drugs
  2. To receive a patient specific advice concerning the use of a drug and the need for precautions

1.  General safety of drugs searches
This type of search is most frequently used. It gives a quick answer when you need to:

  • Find out if a certain drug is generally safe for an acute porphyric patient
  • Find the safest drug for a certain treatment
  • Find a safe alternative for an unsafe drug


Example 1:

Objective: To find out if the beta-antagonist betaxolol can be used by a person who is a gene carrier of one of the acute porphyrias

  1. Choose “Search for information about the general safety of drugs”
  2. Type betaxolol in the field of the generic name. If you are not sure of the spelling of the drug name, you can search using only the first part of the drug name (e.g. betax). It is recommended to type at least 5 characters. Since the search engine uses automatic wild card search, a list of drugs will appear. You can now choose the
    drug you were looking for by clicking on the generic drug name corresponding to the drug in question.
  3. Betaxolol is displayed in a table and the classification is PSP - possibly porphyrinogenic. UNDER the table you
    can find a link with the text "Show alternative drugs in the category beta-blocking agents, selective (BETA BLOCKING AGENTS)". If you want to see the relevant alternatives, you only have to click this button. A new
    table will appear that shows you all the selective beta-blocking agents and how they are classified.
  4. If none of the alternatives are suitable, you can even go further by clicking the button "Show alternative drug groups". If you do this, all cardiac drug classes will appear and you can enter the category you find most relevant by clicking on the name. If you for instance select BETA BLOCKING AGENTS, you will get a table showing all beta blocking agents, including also unselective beta-blocking agents

2.  Patient specific advice

Everyday standard treatment with drugs sometimes turns into a problem because the patient has been diagnosed with an acute porphyria and none of the recommended drugs for treatment of the patient’s disease are classified as safe.

  • The benefit from using a drug should always be assessed against the risk of provoking an acute attack and the likely consequences of not using it.
  • Carriers vary in their susceptibility to drug-induced acute attacks depending on age, gender, and previous and current disease activity.
  • For more serious illnesses, e.g. cancer, a drug treatment should be started.
  • Before prescribing a potentially dangerous drug, it is recommended to seek advice from a porphyria specialist concerning the need for preventive measures and clinical and biochemical follow-up.
  • Porphyria specialists are not available on the telephone 24 hours a day and seven days a week.
  • A system for patient-specific advice has therefore been developed and is included in this database.
  • The database combines clinical data from the patient with the porphyrinogenicity classification of the drug and gives advices for a particular patient concerning the use of the drug, follow-up, and preventive measures.

 

Example 2.1

Case history 1:

Male patient aged 58 with hypercholesterolemia. He had a myocardial infarction a month ago. Treatment with a statin to reduce serum lipid levels is indicated. The problem is, however, that he has an acute intermittent porphyria and that most statins are classified as unsafe (possibly porphyrinogenic or probably porphyrinogenic). Three years ago the patient had an acute attack from his porphyria. He has earlier had increased urinary PBG levels when tested in quiescent phases of the porphyria disease.

As his physician you want to prescribe the drug Pravastatin. Since the drug is classified as possibly porphyrinogenic, you feel insecure. You try in vain to come in contact with a porphyria specialist for an advice.

In a clinical situation like this, you can get an expert like advice using the Drug Database for Acute Porphyria:

  1. Choose the mode for patient specific advice
  2. You are asked to assign your patient to the most relevant risk group based on clinical data. The patient described in case history 1, belongs to the second highest risk group. Just click this risk group.
  3. Type pravastatin in the field of the generic name. It is recommended to type in only the first part of the name (the database uses automatic wild card searching). Use a minimum of 5 characters, i.e. prava.
  4. The result of the search is displayed in a table. To get a patient-specific advice, click on the generic name of the drug you intend to prescribe.

 
For the patient described in case history 1, you will receive the following information and advices:

Patient specific advice concerning the use of the drug Pravastatin

The recommendations take into consideration the porphyrinogenicity classification of the drug as well as the particular patient's vulnerability to potentially porphyrinogenic drugs.

The drug Pravastatin is classified as: Possibly porphyrinogenic (PSP)

For a patient who is assigned to the 'Probably susceptible' risk group, it is recommended to:

  • Tell the patient to observe and immediately report any suspected porphyric symptoms (e.g. abdominal pain) or red urine.
  • Monitor the patient biochemically during the early stages of treatment. This is best performed by daily determination of urinary PBG by a quantitative technique the first 4-6 days after start of medication. A rise in this porphyrin precursor above the upper reference value (or the patient's usual level) is considered strong evidence of an incipient acute attack. Treatment with this drug should then cease at once (unless it is urgently indicated).
  • (Give the patient carbohydrates. Glucose has a protective action against the provoking effect of drugs. Carbohydrates can be administered perorally, in a nasogastric tube or as a parenteral infusion depending on the clinical status of the patient.)

Example 2.2

Case history 2:

Male patient aged 55 with hypercholesterolemia. Recently he had a myocardial infarction and treatment with a statin is indicated. Genetically he is a carrier of acute intermittent porphyria but has no clinical history of porphyria and his urinary PBG is normal.

You want to prescribe the drug Pravastatin, but feel insecure since the drug is classified as possibly porphyrinogenic.
 
Without a history of porphyric symptoms and normal urinary biochemical findings, this patient is expected to be less susceptible to drug-induced acute attacks. Using the mode for patient-specific advice, the database will inform you that:

Patient specific advice concerning the use of the drug Pravastatin

The recommendations take into consideration the porphyrinogenicity classification of the drug as well as the particular patient's vulnerability to potentially porphyrinogenic drugs.

The drug Pravastatin is classified as: Possibly porphyrinogenic (PSP)

For a patient who is assigned to the Probably not susceptible risk group, it is recommended to:

  • Tell the patient to observe and immediately report any suspected porphyric symptoms (e.g. abdominal pain) or red urine.

Please contact us

Our goal is to make the database easy to use for everyone who needs information on drug safety in porphyria. If you still find difficulties in using the database after having read this, please contact us: drugs.porphyria@helse-bergen.no

 





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