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Outpatient Management of Stable Heart Failure with Reduced Ejection Fraction
Published in Andreas P. Kalogeropoulos, Hal A. Skopicki, Javed Butler, Heart Failure, 2023
Leah Reid, Jonathan Murrow, Kent Nilsson, Catherine Marti
Furosemide is the most widely used loop diuretic with an oral bioavailability of about 50% in patients with normal renal function. The onset of action after an oral dose is within 30–60 min and has a duration of action of six hours.42 In renal insufficiency, the elimination half-life can be prolonged and there is reduced drug delivery to the main site of action within the tubule.43 In HF patients, the absorption of oral furosemide can be delayed, which prolongs the time to peak concentration as well as efficacy. Bumetanide is 40 times more potent than furosemide with a bioavailability of 80%. The duration of action is between three and six hours for most patients. Torsemide differs from other loop diuretics as 80% of the drug is metabolized in the liver, so that its half-life is less altered by renal dysfunction. It is absorbed rapidly and has a bioavailability of 80%. The natriuretic response following dosing of torsemide is not affected by route of administration.44 The onset of action is one to two hours after administration with a half-life of 3.3 hours, but this can be prolonged in the setting of cirrhosis.41,45 When selecting an oral agent for patients with HF, torsemide may be advantageous as its absorption is unimpaired and more consistent than that of furosemide.41
Medications
Published in Henry J. Woodford, Essential Geriatrics, 2022
Generally speaking, older people absorb medications similarly to younger people. The main differences in pharmacokinetics occur with drug distribution and elimination. The concentration of albumin in our blood does not change significantly with ageing. Therefore, protein binding is not usually altered. Body composition does change. Older individuals have a higher proportion of body fat and a lower proportion of body water compared to younger people (see page 6). This affects the volume of distribution (Vd) of drugs (i.e. the theoretical volume of fluid that would account for the observed plasma concentration). It is increased for lipophilic drugs and reduced for hydrophilic ones. Sarcopenia can reduce Vd for drugs that bind to muscle. As the half-life of a drug is proportional to its Vd divided by clearance, a larger Vd can increase a drug's half-life. An example of a drug class with a longer half-life for this reason is benzodiazepines.24 Similarly, reduced clearance may have an additional effect.
Medications That May Be Useful in the Management of Patients with Chronic Intractable Pain
Published in Michael S. Margoles, Richard Weiner, Chronic PAIN, 2019
The benzodiazepines contain medications with long half-lives (diazepam) and ones with shorter half-lives (oxepam). Because of the long half-life of diazepam (20–80 hours), a patient might take 5 mg at bedtime for two to four nights and become overly sedated during the daytime hours. On the other hand, some infrequent patients metabolize the medication very quickly and can take 10 mg of diazepam every 4–6 hours without cumulative sedative effects after months to years of taking the medication.
Synthesis and therapeutic delivery approaches for praziquantel: a patent review (2010-present)
Published in Expert Opinion on Therapeutic Patents, 2021
Tayo A. Adekiya, Pradeep Kumar, Pierre P.D. Kondiah, Viness Pillay, Yahya E. Choonara
The pharmacokinetics, which described the movement of PZQ, comprising the absorption, distribution, metabolism, and elimination (ADME) parameters of the drug. The drug is well absorbed by the gastrointestinal tract (GIT) with about 80%, although due to rapid first-pass metabolism, only a relatively small quantity enters systemic circulation. In the adults with normal liver and renal function, the drug has a serum half-life of 0.8 to 1.5 hours. While the metabolites of the drug have a half-life of 4 to 5 hours, the serum half-life increases to about 3 to 8 hours in patients with significant liver function impairments [2,17]. Approximately, 70% to 80% of a single oral dose of PZQ is found in urine within the 24 hours of administration, but less than 0.1% as the unchanged drug. The drug and its metabolites are majorly excreted via the renal route of elimination. PZQ is metabolized via the pathway of cytochrome P450 through the CYP3A4, any bioactive molecules or compounds that inhibit or induce CYP3A4 could influence the PZQ metabolism [17,18].
An overview of PLGA in-situ forming implants based on solvent exchange technique: effect of formulation components and characterization
Published in Pharmaceutical Development and Technology, 2021
Tarek Metwally Ibrahim, Nagia Ahmed El-Megrab, Hanan Mohammed El-Nahas
Nevertheless, many drugs are characterized not only by a high activity but also by a short half-life. The therapeutic value of drugs can be improved by controlling and/or prolonging their release from the pharmaceutical dosage form over time. In this context, sustained-release forms are highly desirable to avoid continuous infusions or frequent injections (Santamaria et al. 2017). These sustained-release preparations display several merits including promoted patient compliance and prevention of peaks and valleys in plasma concentrations, thus allowing the reduction of total dose and minimizing the potential side effects (Parent et al. 2013). On the other hand, conventional oral and transmucosal delivery systems can deliver drugs only within few hours. These systems are less effective for the enhancement of patient compliance especially in the case of daily medication regimens and chronic conditions for a lifetime (Madhav et al. 2009). In addition, non-adherence to oral medications, particularly in psychotic patients, is a deleterious problem that brings out several fluctuations in the plasma concentrations of drugs and retardation of therapeutic outcomes (Kane et al. 2013). Therefore, parenteral sustained release systems are the most promising strategies for achieving the long-term and controlled delivery of drugs.
Addressing challenges in prescribing for vulnerable unsheltered homeless populations with mental illness
Published in Journal of Social Distress and Homelessness, 2021
Lilanthi Balasuriya, Eliza Buelt, William Bruneau, Emma Lo
Medications with longer half-lives offer a variety of benefits including less frequent dosing schedules, less likelihood for withdrawal, and more flexibility with delayed or missed doses. Side effects from missed doses can be notoriously uncomfortable, particularly with treatments such as benzodiazepines and antidepressants with shorter half-lives. When thinking about the barriers such as unpredictable access to shelter, meals, and regular transportation to pick up medications, these added benefits that come along with longer half-lives can be very helpful. Additionally, if patients experience less discomfort with missed doses of medications, they may be more likely to adhere. This should be weighed with the important caveat that medications with longer half-lives will take longer to clear and must be considered carefully in patients with renal or liver disease.