Thursday, January 13, 2005
Accutane Absorbtion Rates
Great post by Gary on Accutane Absorbtion, which was followed up by Rick:
http://health.groups.yahoo.com/group/rosacea-support/message/66501
In a nutshell:
Taking accutane with a meal increases its absorbtion by up to 2x. This has implications for those who are taking, say 20mg every two days and want to minimise the amount utilised by their body.
Quote:
Pharmacokinetics
Absorption
"Due to its high lipophilicity, oral absorption of isotretinoin is enhanced when given with a high-fat meal. In a crossover study, 74 healthy adult subjects received a single 80 mg oral dose (2 × 40 mg capsules) of Accutane under fasted and fed conditions. Both peak plasma concentration (C max ) and the total exposure (AUC) of isotretinoin were more than doubled following a standardized high-fat meal when compared with Accutane given under fasted conditions (see Table 2 below). The observed elimination half-life was unchanged. This lack of change in half-life suggests that food increases the bioavailability of isotretinoin without altering its disposition. The time to peak concentration (T max) was also increased with food and may be related to a longer absorption phase. Therefore, Accutane capsules should always be taken with food (see DOSAGE AND ADMINISTRATION). Clinical studies have shown that there is no difference in the pharmacokinetics of isotretinoin between patients with nodular acne and healthy subjects with normal skin."
http://health.groups.yahoo.com/group/rosacea-support/message/66501
In a nutshell:
Taking accutane with a meal increases its absorbtion by up to 2x. This has implications for those who are taking, say 20mg every two days and want to minimise the amount utilised by their body.
Quote:
Pharmacokinetics
Absorption
"Due to its high lipophilicity, oral absorption of isotretinoin is enhanced when given with a high-fat meal. In a crossover study, 74 healthy adult subjects received a single 80 mg oral dose (2 × 40 mg capsules) of Accutane under fasted and fed conditions. Both peak plasma concentration (C max ) and the total exposure (AUC) of isotretinoin were more than doubled following a standardized high-fat meal when compared with Accutane given under fasted conditions (see Table 2 below). The observed elimination half-life was unchanged. This lack of change in half-life suggests that food increases the bioavailability of isotretinoin without altering its disposition. The time to peak concentration (T max) was also increased with food and may be related to a longer absorption phase. Therefore, Accutane capsules should always be taken with food (see DOSAGE AND ADMINISTRATION). Clinical studies have shown that there is no difference in the pharmacokinetics of isotretinoin between patients with nodular acne and healthy subjects with normal skin."
