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Defining medication adherence in individual patients.

Morrison A, Stauffer ME, Kaufman AS - Patient Prefer Adherence (2015)

Bottom Line: Daily serum concentrations of adalimumab were calculated and compared with a known therapeutic threshold.The four other patients, who took adalimumab at intervals of 7-93 days, could be classified as pharmacokinetically non-adherent, because their adalimumab serum concentration fell below the therapeutic threshold on 3.5%-71.3% of days.Patients with varying patterns of adalimumab dosing could be classified as pharmacokinetically adherent or non-adherent according to whether or not their serum drug concentrations remained within the therapeutic range.

View Article: PubMed Central - PubMed

Affiliation: ScribCo, Effort, PA, USA.

ABSTRACT

Background: The classification of patients as adherent or non-adherent to medications is typically based on an arbitrary threshold for the proportion of prescribed doses taken. Here, we define a patient as pharmacokinetically adherent if the serum drug levels resulting from his/her pattern of medication-taking behavior remained within the therapeutic range.

Methods: We used pharmacokinetic modeling to calculate serum drug levels in patients whose patterns of dosing were recorded by a medication event monitoring system. Medication event monitoring system data were from a previously published study of seven psoriasis patients prescribed 40 mg subcutaneous adalimumab at 14-day intervals for 1 year. Daily serum concentrations of adalimumab were calculated and compared with a known therapeutic threshold.

Results: None of the seven patients took adalimumab precisely every 14 days. Three patients who took adalimumab at intervals of 6-26 days could be classified as pharmacokinetically adherent, because their daily adalimumab serum concentration never fell below the therapeutic threshold. The four other patients, who took adalimumab at intervals of 7-93 days, could be classified as pharmacokinetically non-adherent, because their adalimumab serum concentration fell below the therapeutic threshold on 3.5%-71.3% of days.

Conclusion: Patients with varying patterns of adalimumab dosing could be classified as pharmacokinetically adherent or non-adherent according to whether or not their serum drug concentrations remained within the therapeutic range.

No MeSH data available.


Related in: MedlinePlus

Serum concentration of adalimumab over time for patients whose serum levels (A) did not and (B) did drop below the therapeutic threshold.Notes: Shown are serum levels of adalimumab for each of the seven patients. The timing of each dose for a patient, not specifically indicated in the figure, occurs immediately before each trough point. The bold dashed lines represent the primary therapeutic threshold (4.9 mg/L). The finer dashed lines are alternative cutoffs of 5.4 and 3.6 mg/L.
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f1-ppa-9-893: Serum concentration of adalimumab over time for patients whose serum levels (A) did not and (B) did drop below the therapeutic threshold.Notes: Shown are serum levels of adalimumab for each of the seven patients. The timing of each dose for a patient, not specifically indicated in the figure, occurs immediately before each trough point. The bold dashed lines represent the primary therapeutic threshold (4.9 mg/L). The finer dashed lines are alternative cutoffs of 5.4 and 3.6 mg/L.

Mentions: Serum concentrations of adalimumab are plotted against time in days for patients 1–7 in Figure 1. Three patients (numbers 3, 6, and 7) maintained serum concentrations above the therapeutic threshold of 4.9 mg/L for the entire observation period (Figure 1A). Serum levels fell below the threshold at least some days for patients 1, 2, 4, and 5 (Figure 1B). One patient (number 2) spent 71.3% of the days below the threshold, and two other patients, numbers 1 and 4, fell below the threshold on 23.2% and 31.8% of the days, respectively (Table 1). Patient number 5 fell below the therapeutic threshold only briefly, for 3.5% of the days at the end of the observation period (Table 1).


Defining medication adherence in individual patients.

Morrison A, Stauffer ME, Kaufman AS - Patient Prefer Adherence (2015)

Serum concentration of adalimumab over time for patients whose serum levels (A) did not and (B) did drop below the therapeutic threshold.Notes: Shown are serum levels of adalimumab for each of the seven patients. The timing of each dose for a patient, not specifically indicated in the figure, occurs immediately before each trough point. The bold dashed lines represent the primary therapeutic threshold (4.9 mg/L). The finer dashed lines are alternative cutoffs of 5.4 and 3.6 mg/L.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494613&req=5

f1-ppa-9-893: Serum concentration of adalimumab over time for patients whose serum levels (A) did not and (B) did drop below the therapeutic threshold.Notes: Shown are serum levels of adalimumab for each of the seven patients. The timing of each dose for a patient, not specifically indicated in the figure, occurs immediately before each trough point. The bold dashed lines represent the primary therapeutic threshold (4.9 mg/L). The finer dashed lines are alternative cutoffs of 5.4 and 3.6 mg/L.
Mentions: Serum concentrations of adalimumab are plotted against time in days for patients 1–7 in Figure 1. Three patients (numbers 3, 6, and 7) maintained serum concentrations above the therapeutic threshold of 4.9 mg/L for the entire observation period (Figure 1A). Serum levels fell below the threshold at least some days for patients 1, 2, 4, and 5 (Figure 1B). One patient (number 2) spent 71.3% of the days below the threshold, and two other patients, numbers 1 and 4, fell below the threshold on 23.2% and 31.8% of the days, respectively (Table 1). Patient number 5 fell below the therapeutic threshold only briefly, for 3.5% of the days at the end of the observation period (Table 1).

Bottom Line: Daily serum concentrations of adalimumab were calculated and compared with a known therapeutic threshold.The four other patients, who took adalimumab at intervals of 7-93 days, could be classified as pharmacokinetically non-adherent, because their adalimumab serum concentration fell below the therapeutic threshold on 3.5%-71.3% of days.Patients with varying patterns of adalimumab dosing could be classified as pharmacokinetically adherent or non-adherent according to whether or not their serum drug concentrations remained within the therapeutic range.

View Article: PubMed Central - PubMed

Affiliation: ScribCo, Effort, PA, USA.

ABSTRACT

Background: The classification of patients as adherent or non-adherent to medications is typically based on an arbitrary threshold for the proportion of prescribed doses taken. Here, we define a patient as pharmacokinetically adherent if the serum drug levels resulting from his/her pattern of medication-taking behavior remained within the therapeutic range.

Methods: We used pharmacokinetic modeling to calculate serum drug levels in patients whose patterns of dosing were recorded by a medication event monitoring system. Medication event monitoring system data were from a previously published study of seven psoriasis patients prescribed 40 mg subcutaneous adalimumab at 14-day intervals for 1 year. Daily serum concentrations of adalimumab were calculated and compared with a known therapeutic threshold.

Results: None of the seven patients took adalimumab precisely every 14 days. Three patients who took adalimumab at intervals of 6-26 days could be classified as pharmacokinetically adherent, because their daily adalimumab serum concentration never fell below the therapeutic threshold. The four other patients, who took adalimumab at intervals of 7-93 days, could be classified as pharmacokinetically non-adherent, because their adalimumab serum concentration fell below the therapeutic threshold on 3.5%-71.3% of days.

Conclusion: Patients with varying patterns of adalimumab dosing could be classified as pharmacokinetically adherent or non-adherent according to whether or not their serum drug concentrations remained within the therapeutic range.

No MeSH data available.


Related in: MedlinePlus