(1) State the chosen journal article in the Vancouver referencing format.
Smith WB, Mannaert E, Verhaeghe T, Kerstens R, Vandeplassche L, De Velde VV. Effect of renal impairment on the pharmacokinetics of prucalopride: a single-dose open-label Phase I study [Internet]. 2012 [cited 2015 Sep 01]; 6: 407-415. Available from: www.ncbi-nlm-nih-gov.ezp01.library.qut.edu.au/pmc/articles/PMC3529624/pdf/dddt-6-407.pdf
(2) What were the compounds (and the derivatives if any) under investigation? Provide a brief description about their pharmacology, and the potential uses in medical treatments.
This study concerned the drug prucalopride. Owing to its strong gastrointestinal prokinetic activity, prucalopride is indicated for the symptomatic
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(3) List the objectives of the pharmacokinetic study. What can we learn from studying drugs in the selected population?
The objective of this pharmacokinetic study was to evaluate the pharmacokinetics of prucalopride in individuals with renal impairment. By studying drugs in patients with renal impairment, a greater understanding of the effect of decreased drug renal clearance on drug doses can be made. This is particularly important in the current aging population, whereby decreased renal function is a natural consequent of old age, as is the increased prevalence of constipation associated with drug treatments and lifestyle changes. Considering 60% of prucalopride is excreted unchanged in urine, renal excretion is one of the most important routes of elimination for prucalopride. This further validates the importance of this study in the selected population.
Although prucalopride is not currently approved for use in men, this pharmacokinetic study involved both men and women. This enables results of the study to be applicable for potential future use in men.
(4) Briefly describe the study design including information about the dosage and the route of administration.
The study involved 34 men and women aged 18-75 years old. They were each classified by renal function:
• Normal renal function (creatinine clearance ≥ 80mL/min/1.73m2)
• Mild renal impairment (creatinine clearance 50-79mL/min/1.73m2)
• Severe renal impairment (creatinine clearance ≤
1. first by the conditions that they are used to treat, and then by their mechanisms of action
During Phase 1, sufficient information about the drug’s pharmacokinetics and pharmacological effects should be obtained to permit the design of well-controlled, scientifically valid, Phase 2 studies.
The PPIs are inactive pro drugs that are carried in the bloodstream to the parietal cells in the gastric mucosa. The pro drugs readily cross the parietal cell membrane in the cytosol. These drugs are weak bases and therefore have a high affinity for acidic environments. They diffuse across the secretory membrane on the parietal cell into the extracellular secretory canaliculus, the site of active proton pump. Under this acidic conditions the prodrugs are converted to their active form, which irreversibily binds the proton pump, inhibiting acid secretions. Since the’ active principles ‘ forms at a low pH it concentrates selectively in the acidic enviorment of the proton pump and results in extremely effective inhibition of acid secretion.The different PPIs(Omeprazole,Esomeprazole,Lanzoprazole, Pantoprazole and Rabeprazole ) bind to different sites on the proton pump, which may explain their differences in potency on a milligram per milligram basis.
The National Prescribing Centre recognize some fundamental differences in the absorption, distribution and excretion of medicines between adults and children. The differences are published in the National Prescribing Centre’s bulletin, produced by
Dosing. Physiologic changes in the elderly make medication dosing tricky. Adjustments have to be made owing to age-related reduction in liver and kidney functions, as well as the presence of coexisting comorbidities and use of other medications for these pre-existing conditions. The BEERS list, a compilation of potentially harmful medications to the elderly, was drafted in an attempt to curb the rising incidence of avoidable adverse medication effects in this population.
Adverse drug events include adverse drug reactions (ADRs); drug-drug interactions due to uncertainty about the benefits and harms of simultaneous treatment; drug-disease interactions due to potential risk of worsening one condition by treating a co-existing one; improper drug election, sub- and supra-therapeutic dosage, noncompliance/failure to receive drug, and wrong drug (10, 13-16). Older adults are at increased risk for developing adverse drug events due to multiple concurrent diseases and physiological changes that occur as part of the ageing process, particularly, in pharmacokinetics (reduced renal elimination) and pharmacodynamics (increased sensitivity to certain medications) affecting drug disposition (10).
This was the simplest way to obtain all the drug information needed from the package insert. The approved indication for this drug is PAH for patients in WHO functional classes II-III. Treprostinil is classified as a prostanoid drug meaning that its mechanism of action causes vasodilation of arterioles, which halts proliferation of smooth muscle cells and platelet aggregation. For patients without hepatic impairment, treprostanil is started at a dose of 0.25 mg BID or 0.125 mg TID. Every 3-4 days the dose is increased by 0.25-0.5 mg BID or 0.125 mg TID. The goal is to titrate up to the maximal tolerated dose. The use of treprostinil is contraindicated in patients with moderate to severe hepatic impairment (Child Pugh Class B and C), but can be used for those with mild impairment (Child Pugh Class A). In this case, the initial dose would be 0.125 mg BID and is increased by 0.125 mg BID every 3-4 days as the patient can tolerate. Oral treprostinil has a 17% bioavailability, with maximum concentration occurring approximately 4 to 6 hours after administration. The absorption of this drug is increased with the administration of food. The AUC increased by 49% and the Cmax by 13% following a meal in healthy participants. Also, treprostinil is highly protein bound. The drug is mainly hepatically metabolized by enzyme CYP2C8 and is excreted mostly as metabolites and very little as the parent drug. Treprostinil has drug interactions with anti-hypertensive medications due to risk of hypotension and CYP2C8 inhibitors. Common adverse effects include: headache, diarrhea, nausea and flushing. Rare adverse drug reactions include: hypokalemia, pain in jaw and abdominal discomfort. Precautions and warnings are an increased risk of bleeding, rebound PAH symptoms after sudden discontinuation, increased drug release when taken with alcohol, and aggravation of
The population mean value for lenvatinib CL/F was estimated to be 6.56 L/h (% CV 25.5), which was independent of dose (3.2 mg to 32 mg) and time. The capsule formulation had a 10.4% lower bioavailability relative to the tablet formulation. The final population PK model also included significant effects of body weight, population (healthy vs patients with cancer), liver-function markers (ALP and albumin), and concomitant administration of CYP3A4 inducers and inhibitors on lenvatinib CL/F (Table 2). Lenvatinib CL/F increased with increasing body weight (power function = 0.75). Body weight was added as an allometric constant on CL/F and volume parameters and showed a statistically significant effect but only explained 2.8% of the IIV on CL/F. Healthy subjects had a 15% higher lenvatinib CL/F than patients with cancer, lenvatinib CL/F decreased by 11.7% with ALP > the upper limit of normal and decreased by 16.3% with albumin levels < 30 g/L, concomitant administration of CYP3A4 inducers increased lenvatinib CL/F by 30%, and CYP3A4 inhibitors decreased lenvatinib CL/F by 7.8%. Conversely, sex, race, age, ECOG PS, renal-function markers (creatinine clearance and CTC grades for renal function), liver-function markers (ALT, AST, bilirubin, and CTC grades for liver function), and thyroid-function marker (TSH) had no significant effect on lenvatinib CL/F (Table 2). Additionally, drugs that raise gastric pH
In Phase I study the safety of a drug or device is a priority and this initial testing phase can take several months to complete and generally includes 20 to 100 paid healthy volunteers in study. The design of the study is to determine the effects of the drug or device on humans including how it is absorbed, metabolized, and excreted. The investigation of a side effects also observed by an increasing the drug doses. Not all drugs are passing during this phase, but nearly 70% of
For elderly people the pharmacokinetics varies. A study was conducted that included evaluating 22 elderly volunteers (>65 years old) receiving a 50 mg oral dose of the drug (4). The peak plasma concentration was 1.54 mcg/mL and it took place 1.3 hours after the dose. The area under the curve (AUC) for the elderly volunteers was 76.4 mcg*h/mL. Compared to young individuals the AUC was much greater for the elderly, suggesting that the ability to clear out the drug decreases in elderly patients thus more of it is absorbed in the body (4). Furthermore, creatinine clearance and the amount of drug recovered in the urine were also much lower in the elderly because of the reduced renal function (4). In normal volunteers, the drug was mainly cleared by the kidneys with around 80% of the drug that was administered appearing in the urine as unchanged (1).
Give the subject comprehensive information about the new drug, including its side effects. Discuss the pros and cons of both the investigational drug and the commercially available drug and then allow the subject to decide whether to withdraw from the research to take the new drug.
Throughout history many population groups have been excluded from drugs trials. The populations include elderly, African Americans, women, pregnant women, and children. Because they have been excluded we do not know the side effects of many medications that are giving to this population. This paper will concentrate on the history, what is being done currently, what are the plans in the future and how nurses can support women in medication trials.
Other research conducted on the use of PRN medication includes retrospective studies in which case notes were audited and administration practices were examined.9-10 Other studies have looked at antecedents to PRN administration, activities to reduce PRN medication administration and literature
Zachariah et al. (2009) in addition to Rosenhoff et al. (2006) and Hoff et al. (2014) who had similar sample sizes, ranging between 139 to 215 participants all found octreotide was not more effective than loperamide within the same days of administration when both drugs were used to treat patients undergoing chemotherapy or radio-chemotherapy. Specifically, Rosenhoff et al. compared two different dosages of octreotide SQ in patients who had failed loperamide therapy in the past, demonstrated a 15% decrease in CID which failed to reach statistical significance (P=0.14). All three studies had very specific inclusion and exclusion criteria in order to remove any potential skew of results due to disease side effects such as diabetes mellitus, irritable bowel syndrome, or any reported chronic laxative use. All
Bivalirudin pharmacokinetics and pharmacodynamics have been studied in the setting of renal impairment (16). In mild renal impairment, plasma clearance of bivalirudin was not significantly decreased when compared with normal kidney function. However, in moderate and severe renal impairment, the plasma clearance of bivalirudin reduced 21% and 24%, respectively (16).