With or without food
U2 Cover (With or Without You) (source: Google)

With or without food

One of my favorite songs when I was young was 'With or Without You' by U2. The chorus goes:

'With or Without You, With or Without You, oh, I Can't Live, With or Without You'

Guess what? If we understand our #pharmacokinetics #concepts (#5), we can predict the oral absorption of drug with or without food. The chorus of the new song will go:

'With or Without Food, With or Without Food, oh, I Can Predict, With or Without Food'

As a recap, the absorption of all acidic, basic and neutral drugs is faster from the small intestine than from the stomach. To revise this concept, you may refer to article #4.

Consequently, how fast the stomach empties its content into the small intestine (aka gastric emptying rate) becomes an important controlling step to regulate the rate and extent of systemic absorption of orally-administered drugs. During fasting (no food), the average stomach transit time of a tablet is around 1 hour. During fed (heavy breakfast), the average stomach transit time can go up to 7 hours! For a membrane-permeable drug that is sparingly soluble in both gastric and intestinal fluids, administering the drug with food will help to improve its absolute oral bioavailability (F). #True or #False?

#True. With a fixed short transit time in the small intestine (3-4 hours), the slow release of drug from the stomach under fed condition, increases the time for drug to dissolve before entering the intestine, thereby favoring increased oral bioavailability. The bile salts that are released after a high fat meal further act as surfactants and enhance solubility of the sparingly soluble drug.

In summary, food slows down gastric emptying rate, improves the dissolution of sparingly soluble drug, reduces its rate but increases its extent of absorption and increases its oral bioavailability. The higher oral bioavailability will lead to higher systemic exposure (AUC) which in turn correlates with the pharmacology (drug) effects. Of course, this is just one scenario and there are many other scenarios related to pro-drugs, soluble drugs, enteric-coated drugs, sustained-released drugs etc.

In conclusion, it is important to appreciate that when pharmacists and physicians advise us to consume oral drugs with or without food, we need to be compliant as food has important effects on pharmacokinetics. If you like to learn more about the 'very' basic concepts in?#pharmacokinetics, let me know and follow my future posts.

#Pharmacokinetics?#Concepts?#LearningWithoutBarriers #WeeklyDoseOfPK

要查看或添加评论,请登录

Eric Chan, PhD的更多文章

  • Binding to the railway track

    Binding to the railway track

    This picture taken by my son, Ethan, at the Clementi Forest in Singapore shows a silhouette of a hiker with one leg…

    2 条评论
  • Tug-of-war

    Tug-of-war

    The aim of discussing basic #pharmacokinetics #concept #9 is to appreciate how the differential binding of drug to…

    8 条评论
  • TGIF

    TGIF

    TGIF! Let’s continue to discuss basic #pharmacokinetics #concept #8 Previously, we learned that the total tissue drug…

    7 条评论
  • Equilibrium Does Not Mean Equal

    Equilibrium Does Not Mean Equal

    I am proud that my second son is completing his 2 years national service with the Singapore Armed Forces this coming…

    7 条评论
  • What does the F word mean to you?

    What does the F word mean to you?

    What comes to your mind when you read ‘The F Word’? For some, ‘The F Word’ is a British cookery programme or an…

    9 条评论
  • Does pH-partition hypothesis govern all ADME processes of drugs?

    Does pH-partition hypothesis govern all ADME processes of drugs?

    This week, I wrote an op-ed article on synthetic cannabis which was published by the Straits Times on October 6, 2022…

    2 条评论
  • A drug that is administered into muscle does not need to be systemically absorbed. True or false?

    A drug that is administered into muscle does not need to be systemically absorbed. True or false?

    This weekend Singapore is organizing the 2022 Singapore Grand Prix! It is a Formula One (F1) motor race scheduled to be…

    10 条评论
  • What is the relationship between systemic exposure and absolute oral bioavailability?

    What is the relationship between systemic exposure and absolute oral bioavailability?

    Last week I posted my first newsletter article and the responses are encouraging. I am also glad that there are more…

    4 条评论
  • What does ADME stand for?

    What does ADME stand for?

    My friend, Dr. Masoud Jamei, Senior VP of R&D at Certara UK, Simcyp Division, has suggested that I write and publish my…

    6 条评论

社区洞察

其他会员也浏览了