China
Africa
Explore chapters and articles related to this topic
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
Bioavailability and Granule Properties
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
The elimination rate constant (K) is constant for a drug in normal healthy individuals, and it changes when organs responsible for the elimination of the drug (i.e., kidney and liver) exhibit abnormalities. The absorption rate constant (Ka), on the other hand, depends on the route of administration, the dosage form, and the formulation of a drug. And, for hydrophobic drugs and/or when the absorption and dissolution rate is limited, the faster dissolution is generally reflected in the higher value for the absorption rate constant. Therefore, by changing the formulation of a drug or route of administration, one can alter the peak time and the rate of absorption and time for the onset of action.
The Pharmacotherapy of Rhinitis and Asthma
Published in Pudupakkam K Vedanthan, Harold S Nelson, Shripad N Agashe, PA Mahesh, Rohit Katial, Textbook of Allergy for the Clinician, 2021
Amanda Grippen Goddard, Harold S. Nelson, Rohit Katial, Flavia Hoyte
Two intranasal antihistamines preparations are available (azelastine and olopatadine). Their onset of action is within 15 to 30 minutes. In comparison studies they have proven of equal or occasionally slightly superior efficacy to the second-generation oral antihistamines (Wallace and Dykewicz 2008). Intranasal antihistamines are equally effective but faster in onset of action as compared with intranasal corticosteroids (Kaliner et al. 2009). In one study comparing intranasal azelastine to intranasal fluticasone, intranasal fluticasone was superior to reducing rhinorrhea, but intranasal azelastine showed comparable efficacy for all other nasal and ocular symptoms. Additionally, compared to baseline ocular symptoms, there was a larger percentage (53.0%) of patients on intranasal azelastine as opposed to intranasal fluticasone (39.6%) that exhibited a 50% reduction in reflective total ocular symptom score by day 14 of treatment (Carr et al. 2012b). The use of intranasal antihistamines in combination with intranasal corticosteroids demonstrates additional symptom reduction and improved quality of life as compared to intranasal antihistamine monotherapy (Brozek et al. 2017). Intranasal antihistamines may have greater efficacy for nasal congestion than oral antihistamines (Brozek et al. 2017). Azelastine is associated with taste perversion and somnolence in some patients (Bousquet et al. 2008), while these symptoms are less frequent with olopatadine (Lieberman et al. 2011).
Clinical pharmacology of antiplatelet drugs
Published in Expert Review of Clinical Pharmacology, 2022
Georg Gelbenegger, Bernd Jilma
Ticagrelor is a specific, potent and reversible P2Y12 inhibitor of the cyclopentyltriazolopyrimidine (non-thienopyridine) class. Ticagrelor does not require metabolic activation, binds rapidly to the P2Y12 receptor, but uses a binding site distinct from the ADP-binding site (noncompetitive inhibition) [112]. Binding of ticagrelor to the P2Y12 receptor locks the receptor in an inactive state, inhibiting ADP-induced conformational change of the P2Y12 receptor, consequent activation of receptor-coupled G proteins and ADP signaling [113]. Ticagrelor is further metabolized by CYP3A4 and CYP3A5 [114] into the active metabolite AR-C124910XX, which is equipotent to its parent compound [115,116]. Under normal circumstances, ticagrelor is rapidly absorbed and induces maximum inhibition of platelet aggregation after 2 hours [117]. Onset of action occurs within 30 minutes to 4 hours [110]. The antiplatelet effect of ticagrelor lasts for 3–5 days [110]. Concomitant intake of food does not impact the antiplatelet effect of ticagrelor [118] (Table 2).
Investigational drugs for assisting psychotherapy for posttraumatic stress disorder (PTSD): emerging approaches and shifting paradigms in the era of psychedelic medicine
Published in Expert Opinion on Investigational Drugs, 2022
Lynnette A. Averill, Chadi G. Abdallah
The unfortunate reality of the mental health crisis plaguing much of the world, in tandem with and exacerbated by the COVID-19 pandemic [1–3], highlights the limited effective pharmacologic treatments in our toolbox for posttraumatic stress disorder (PTSD). There are only two FDA-approved medications indicated for PTSD, both selective serotonin reuptake inhibitors (SSRIs). Though these traditional medications work very well for a restricted population, they have significant limitations [4]. Even when optimally delivered, 40% of the patients do not respond to SSRIs, and only about 20% to 30% achieve remission, and the magnitude of the difference from placebo ranges from 10% to 20% [5,6]. The rates of non-response or partial response to these medications among combat-exposed individuals, particularly those with chronic PTSD, are comparable or worse to those of civilian patient populations [7,8]. Further, even when traditionally available SSRIs are effective, they are slow-acting antidepressants (SAADs) with a delayed onset of action, meaning it can take weeks to months before patients experience clinical benefit. This latency period is quite troubling as it significantly increases the risk for suicide and self-harm as well as other destructive behaviors [9].
Evaluating revefenacin as a therapeutic option for chronic obstructive pulmonary disease
Published in Expert Opinion on Pharmacotherapy, 2020
Sabina Antonela Antoniu, Ruxandra Rajnoveanu, Ruxandra Ulmeanu, Florin Mihaltan, Mihaela Grigore
In vivo testing comparatively evaluated the pharmacological properties (bronchodilating potency, duration of action, and M3 selectivity) of TD-4208, glycopyrronium, and tiotropium in rats and dogs separately for single or repeated (seven) doses. Bronchodilating potency and onset of action at various single doses (3, 10, and 30 mg/kg) of inhaled TD-4208 were tested in dogs. A dose-dependent bronchodilating effect, which was significantly superior to that of placebo (inhaled vehicle), was observed. The onset of action for all doses was 5 min after dosing. The duration of bronchodilating effect was also found to be dose dependent, with only two higher doses resulting in >24 h sustained inhibitory effects. The other two LAMAs tested were also found to exert significant antimuscarinic effects compared with placebo [8,9]. Similar effects were found with both single and multiple doses on methacholine-induced bronchoconstriction in rats. The dose producing 50% inhibitory effect (ID50) was 45 mg/mL with single dosing and 36 mg/mL for repeated dosing.