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PubMed1990

In vitro release profile of estradiol transdermal therapeutic systems.

The in vitro release profiles of two sizes of estradiol patches were determined by the paddle method, where the patch was held in position at the bottom of the dissolution vessel by sandwiching it between a watch glass and an aluminum wire mesh or Teflon screen, and also by the manufacturer's paddle-over-disk method. The estradiol content of test aliquots of the dissolution medium was determined by HPLC. The release profiles by both procedures were comparable and showed that approximately 10% of the labeled drug was released in 4 days.

Administration, Cutaneous↗
PubMedDate not supplied

Antihypertensive effects of a new transdermal delivery system for clonidine (M-5041T) in spontaneously hypertensive rats.

The antihypertensive effects of a new transdermal delivery system for clonidine (clonidine tape; M-5041T) were investigated in spontaneously hypertensive rats and normotensive Wistar-Kyoto rats. In spontaneously hypertensive rats, M-5041T, at doses of 0.5-4.5 mg/kg (1.25-11.25 cm2/kg), produced a dose-dependent decrease of both systolic blood pressure and heart rate for 24 hr during transdermal application. These significant hypotensive effects lasted for 24 hr following the patching of M-5041T on the back of the animals at a dose of 4.5 mg/kg. In normotensive Wistar-Kyoto rats, the hypotensive and bradycardic effects of M-5041T were weak compared with those in spontaneously hypertensive rats. In both rat strains, M-5041T (4.5 mg/kg) caused behavioral changes such as sedation, piloerection and exophthalmos, accompanied by hypotensive effects. Both M-5041T (1.5 mg/kg) and clonidine (50 micrograms/kg, subcutaneously and 100 micrograms/kg, orally) induced similar hypotensive effects, accompanied by sedation. The hypotensive effects following transdermal M-5041T or systemic clonidine administrations were correlated with the time courses of the plasma clonidine concentration. In contrast to clonidine administered subcutaneously or orally, M-5041T produced a gradual increase in the plasma clonidine concentration, which persisted at a consistent level for at least 12 hr thereafter. Significant hypotensive effects lasted for 12 and 24 hr following M-5041T patching at 1.5 and 4.5 mg/kg, respectively. The present findings suggest that M-5041T can serve as an efficient and useful antihypertensive transdermal delivery system to achieve persistent blood pressure control.

Administration, Cutaneous↗
PubMed2002

Double-blind evaluation of transdermal nitroglycerine as adjuvant to oral morphine for cancer pain management.

STUDY OBJECTIVES: To examine analgesia and adverse effects following transdermal application of nitroglycerine (a nitric oxide generator) combined with oral morphine, in cancer pain patients. DESIGN: Randomized, double-blind study. SETTING: Teaching hospital. PATIENTS: 36 patients suffering from cancer pain. INTERVENTIONS: Patients were divided into two groups (n = 18). All patients were regularly taking oral amitriptyline 50 mg at bedtime. Pain was evaluated using a 10-cm visual analog scale (VAS). The morphine regimen was individually adjusted to a maximal oral dose of 80 to 90 mg/day, to maintain the VAS score less than 4/10 cm. When patients complained of pain (VAS equal or greater than 4/10), despite taking 80 to 90 mg of oral morphine daily, the transdermal test drug was supplemented as follows: the control group received a placebo patch daily, and the nitroglycerine group received a 5-mg/24-hour nitroglycerine patch daily. Patients were free to manipulate their daily morphine consumption at the time the test drug was administered, to keep VAS less than 4/10 cm. After the introduction of the transdermal test drug, patients were evaluated by the staff on a weekly basis as outpatients, over four consecutive weeks. MEASUREMENTS AND MAIN RESULTS: The groups were similar in respect to demographic data and VAS pain scores before the treatment. The daily consumption of oral morphine was smaller in the nitroglycerine group compared with the control group after the 14th day of evaluation (p < 0.002). Patients from the control group in general complained of somnolence, compared with the nitroglycerine group. CONCLUSION: Transdermal nitroglycerine was an effective coadjuvant analgesic. In conjunction with its opioid tolerance sparing function, delivery of nitric oxide donors together with opioids may be of significant benefit in cancer pain management in delaying morphine tolerance and decreasing the incidence of adverse effects related to high doses of opioids.

Administration, Cutaneous↗
PubMed2002

The lipid and clinical effects of sequential transdermal estradiol and estradiol/norethisterone acetate in 674 women.

OBJECTIVE: To measure lipid changes induced by patches delivering continuous estradiol (E(2)) and sequential norethisterone acetate (NETA) in a large population of symptomatic menopausal women, compared with a non-symptomatic control group. PATIENTS AND METHODS: A total of 748 women recruited in 42 different hospital services and clinics in Spain were invited to participate in a prospective, open, controlled study for 48 weeks. Six hundred and seventy-four women were evaluated in the treatment group, and 74 in the control group. Treatment consisted of patches delivering 0.05 mg/day E(2) for the first 14 days of the cycle, and 0.05 mg/day E(2) plus 0.25 mg/day NETA for another 14 days. RESULTS: Use of patches led to a slight, but significant decrease of 1.3% and 0.9% in concentrations of total cholesterol and low-density lipoprotein cholesterol (LDL-C), respectively. A substantial 37.0% decrease in triglycerides concentration was observed in treated women. The treatment effectively reduced climacteric symptoms (Kupperman index) for the duration of the study. Compliance was acceptable, with 489 (72.6%) women completing the study. Adverse events were reported by 137 (20.3%) women. CONCLUSIONS: Transdermal administration of E(2) and sequential NETA for a period of 48 weeks (twelve 28-day cycles) was associated with beneficial changes, albeit of differing magnitudes, in the concentration of total cholesterol, LDL-C and triglycerides. This protective lipid profile, together with satisfactory clinical efficacy and acceptable safety and compliance, makes this system a good alternative in hormone replacement therapy.

Administration, Cutaneous↗
PubMed2001

A short-term, multicenter, randomized double-blind dose titration study of the efficacy and anticholinergic side effects of transdermal compared to immediate release oral oxybutynin treatment of patients with urge urinary incontinence.

PURPOSE: We compared the short-term efficacy, safety and tolerability of transdermal versus oral oxybutynin in adults with urge urinary incontinence. MATERIALS AND METHODS: Volunteers with detrusor instability currently responding to oral immediate release oxybutynin were enrolled in our study. Those patients presenting with recurrence of incontinent symptoms after a 2-week washout underwent confirmatory cystometrogram with subsequent randomization to transdermal or oral treatment. Matching active and placebo medications included matrix patches applied twice weekly and capsules taken 2 or 3 times daily. Dose titration was based on anticholinergic symptoms. Outcome measures included comparison of baseline to 6 week changes in incontinence episodes on a 3 day urinary diary, a visual analog scale for efficacy and anticholinergic symptoms reported on a questionnaire. Safety monitoring included adverse events and skin tolerability of the transdermal system. RESULTS: A total of 76 patients were enrolled and 74 completed at least 4 weeks of treatment. Mean age in the transdermal and oral groups was 64 and 63 years, and 87% and 97% were female, respectively. Daily incontinent episodes decreased in the transdermal and oral groups (7.3 to 2.4 [66%] and 7.4 to 2.6 [72%], respectively, p = 0.39). The visual analog scale reduction in urinary leakage improved from washout in both groups (p <0.0001) with no difference between them (p = 0.9). Dry mouth occurred in significantly fewer patients in the transdermal (38%) compared with those in the oral group (94%, p <0.001). Of the patients in the transdermal group 67% noticed a reduction in dry mouth severity compared with previous oral treatment, and 90% had none or mild skin erythema. CONCLUSIONS: Transdermal delivery of oxybutynin resulted in comparable efficacy and a significantly improved anticholinergic side effect profile compared with oral administration in adults with urge urinary incontinence.

Administration, Cutaneous↗
PubMed2003

Systemic scleroderma patients have improved skin perfusion after the transdermal application of PGE1 ethyl ester.

BACKGROUND: Patients with systemic scleroderma exhibit a noticeable slowing of blood cell velocities or even stasis in the capillaries of the skin. In this study the effects of transdermally applied prostaglandin PGE1 ethyl ester on nutritive cutaneous perfusion and on Raynaud's symptoms were investigated. PATIENTS AND METHODS: 24 patients with systemic scleroderma were treated transdermally over a period of 14 days with prostaglandin E1 ethyl ester patches. The response of blood cell velocity in the nailfold capillaries to cold exposure was tested in 20 patients, and all of the patients recorded the number of Raynaud's episodes in a journal over a period of two weeks. RESULTS: After the transdermal application of prostaglandin E1 ethyl ester there was an increase in blood cell velocity in the nutritive capillaries of systemic scleroderma patients (increase from 0.35 +/- 0.14 mm/s to 0.47 +/- 0.11 mm/s, (p < 0.05)). At the same time there was a decrease in the number of Raynaud's episodes (2.9 +/- 2.4 per day to 2.6 +/- 2.0 per day (p < 0.05)). CONCLUSION: The transdermal application of prostaglandin E1 ethyl ester was shown to have a favourable effect on nutritive blood flow in the capillaries of the skin in systemic scleroderma patients.

Administration, Cutaneous↗
PubMed1994

The pros and cons of transdermal nicotine therapy.

OBJECTIVE: To review current knowledge of the efficacy, safety and cost of transdermal nicotine therapy for smoking cessation. DATA SOURCES AND STUDY SELECTION: 1. Published and unpublished reports of randomised, double-blind trials of at least 12 weeks' duration, in smokers motivated to cease smoking, identified by a search of the MEDLINE database, article and book bibliographies, Current contents, and by a request to the Medical Department of Ciba-Geigy (Australia) Ltd. 2. A clinical trial of 1500 smokers using transdermal nicotine (S Gourlay, unpublished data). DATA SYNTHESIS: Transdermal nicotine more than doubles the success rates of smoking cessation attempts in motivated subjects who smoke at least 10-15 cigarettes per day (odds ratio 12 months after quitting, 2.3; 95% confidence interval, 1.6-3.4). Application site reactions are not uncommon (erythema or burning < or = 16%, transient itch < or = 50%) and cause discontinuation of therapy in up to 10% of subjects. Sleep disturbance due to nocturnal nicotine absorption occurs in up to 13% of subjects when patches are worn overnight. Smoking or nicotine chewing gum used concurrently with transdermal nicotine could raise peak nicotine levels but is unlikely to adversely affect individuals with established tolerance to nicotine. Smoking and (theoretically) nicotine replacement therapies should be avoided in pregnancy or patients with unstable coronary artery disease. In such patients, the risk-benefit ratio of nicotine replacement therapies may be favourable for nicotine-dependent smokers unable to cease smoking by alternative methods. CONCLUSIONS: Transdermal nicotine is an effective smoking cessation therapy for motivated, nicotine-dependent smokers. As most smokers can cease smoking on their own, and the patches are costly, they should be recommended only for smokers who are unable to quit by simpler means and those likely to suffer severe nicotine withdrawal symptoms.

Administration, Cutaneous↗
PubMed1995

Varying nicotine patch dose and type of smoking cessation counseling.

OBJECTIVE: To compare the efficacy and safety of 22-mg and 44-mg doses of transdermal nicotine therapy when it is paired with minimal, individual, or group counseling to improve smoking cessation rates. DESIGN: An 8-week clinical trial (4 weeks double-blind followed by 4 weeks open label) using random assignment of participants to both dose (22 or 44 mg) and counseling (minimal, individual, or group) conditions. PARTICIPANTS: Daily cigarette smokers (> or = 15 cigarettes per day for at least 1 year) who volunteered to participate in a study of smoking cessation treatment. A total of 504 participants were enrolled at two sites. INTERVENTION: Four weeks of 22- or 44-mg transdermal nicotine therapy followed by 4 weeks of dosage reduction (2 weeks of 22 mg followed by 2 weeks of 11 mg). Counseling consisted of a self-help pamphlet (minimal); a self-help pamphlet, a brief physician motivational message, and three brief (< 15 minutes) follow-up visits with a nurse (individual); or the pamphlet, the motivational message, and eight weekly 1-hour group smoking cessation counseling visits (group). All participants returned weekly to turn in questionnaires and for assessment of their smoking status. MAIN OUTCOME MEASURES: Abstinence from smoking was based on self-report, confirmed by an expired carbon monoxide concentration lower than 10 ppm. Withdrawal severity was assessed by means of an eight-item self-report questionnaire completed daily. RESULTS: Smoking cessation rates for the two nicotine patch doses and three levels of counseling did not differ significantly at either 8 weeks or 26 weeks following the quit date. Among those receiving minimal contact, the 44-mg dose produced greater abstinence at 4 weeks than did the 22-mg dose (68% vs 45%; P < .01). Participants receiving minimal-contact adjuvant treatment were less likely to be abstinent at the end of 4 weeks than those receiving individual or group counseling (56% vs 67%; P < .05). The 44-mg dose decreased desire to smoke more than the 22-mg dose, but this effect was not related to success in quitting smoking. Transdermal nicotine therapy at doses of 44 mg produced a significantly greater frequency of nausea (28%), vomiting (10%), and erythema with edema at the patch site (30%) than did a 22-mg dose (10%, 2%, and 13%, respectively; P < .01 for each adverse effect). Three serious adverse events occurred during use of the 44-mg patch dose. CONCLUSIONS: There does not appear to be any general, sustained benefit of initiating transdermal nicotine therapy with a 44-mg patch dose or of providing intense adjuvant smoking cessation treatment. The two doses and all adjuvant treatments produced equivalent effects at the 26-week follow-up, and the higher patch dose produced more adverse effects. Higher-dose (44-mg) nicotine replacement does not appear to be indicated for general clinical populations, although it may provide short-term benefit to some smokers attempting to quit with minimal adjuvant treatment.

Administration, Cutaneous↗
PubMed1994

Transdermal scopolamine for reduction of drooling in developmentally delayed children.

Ten developmentally delayed children with excessive drooling were randomized in a double-blind, placebo-controlled study to assess the efficacy and safety of transdermal scopolamine. Over half of the patients had a statistically significant reduction in drooling, and one-third had cessation of drooling, while wearing the scopolamine patch. This short-term study supports earlier reports of the safety and efficacy of transdermal scopolamine for reducing excessive drooling in developmentally disabled children.

Administration, Cutaneous↗
PubMed2005

Inter- and intra-individual variability in transdermal fentanyl absorption in cancer pain patients.

A transdermal therapeutic system (TTS) is recommended for use in chronic cancer pain, particularly in the advanced stages. The aim of this trial was to study intra- and interindividual variabilities in fentanyl transdermal absorption and investigate physiological and clinical parameters that can influence the absorption in patients treated using a TTS for moderate to severe cancer pain. The study group consisted of 108 patients (71 men and 37 women; mean age, 61.3 years) with chronic cancer pain. A total of 507 patches were analysed. The TTSs used to administer fentanyl were removed after a 72-h period. The amount of fentanyl remaining in the patches was determined using a high-performance liquid chromatography method with ultraviolet detection. Depending on the analgesic requirements of the patient, the dose of fentanyl administered by TTS ranged from 25 to 500 microg/h. The study period was 6 months. Large interindividual variability in the amount of remaining fentanyl in the patches occurred. For 58.1% of patches, absorption was 60 to 84%; for 33.2% of them, it was lower; and for 8.8%, it was higher than this range. The intra-individual variability ranged from 2.8 to 75.1%. The bioavailability of fentanyl was statistically different according to patient age. Patients >75 years of age absorbed 50% of the fentanyl during the selected 72-h period, whereas patients <65 years absorbed 66%. Moreover, there is a significant difference in the percentage of absorbed fentanyl according to the type of cancer. The absorption was higher in patients with breast or digestive cancer than in those with lung cancer. Hyperhidrosis, hypertrichosis and the localization of patches on the skin did not influence bioavailability. For the entire group, transdermal fentanyl treatment provided good to excellent pain relief in the majority of patients.

Administration, Cutaneous↗
PubMed1985

The use of transcutaneous clonidine hydrochloride in the patient with diabetes mellitus and mild hypertension.

The effectiveness and safety of transdermally administered clonidine hydrochloride was assessed in 16 patients with type-II diabetes mellitus. This group of patients was chosen because of the frequent occurrence of hypertension in diabetic patients and potential problems with transdermal absorption of medication because of small vessel disease. A skin patch containing clonidine hydrochloride (Catapres TTS) was applied at weekly intervals after an appropriate placebo lead-in period. Satisfactory response to therapy was seen in 15 of the 16 patients. One patient developed a generalized skin rash and was withdrawn from the study. Correlation between change in diastolic blood pressure and plasma clonidine levels was noted. Of note was the absence of the usual side effects (drowsiness, dry mouth, etc.) seen with oral clonidine administration. This study thus highlights the success of transdermal clonidine therapy in controlling blood pressure in the mild hypertensive patient with diabetes mellitus.

Administration, Topical↗
PubMed2002

Allergic contact dermatitis from transdermal estradiol and systemic contact dermatitis from oral estradiol. A case report.

BACKGROUND: About 20% of patients using transdermal estradiol complain of adverse local side effects. CASE: A 47-year-old, postmenopausal woman developed eczematous lesions at the sites of application of a estradiol therapeutic transdermal system and successively at the sites of application of a gel containing estradiol. Due to the topical intolerance, the therapy was switched to oral estrogen, which caused a systemic pruritic rash. Positive patch tests with estradiol led to the diagnosis of type IV allergic dermatitis due to transdermal estradiol and to a gel containing estradiol. Systemic contact dermatitis due to oral estradiol was also diagnosed. CONCLUSION: Even though allergic contact dermatitis from estradiol is extremely rare, local side effects from estradiol systems must be kept in mind and correctly diagnosed. Patch tests allow identification of the causative agent. In the case of primary sensitization to topical estradiol, oral estrogens must be prescribed cautiously to avoid systemic reactions.

Administration, Cutaneous↗
PubMed2001

Is transdermal drug delivery research still important today?

When measured by the number of medicines consumed or prescriptions written, the topical and transdermal routes of drug delivery pale into insignificance compared with oral therapy. Industrial colleagues, therefore, occasionally adopt a somewhat utilitarian stance and question the value of academic research into skin treatment and drug permeation, with the rather parochial argument that it is of limited use to the UK pharmaceutical industry. To consider the validity of this somewhat dismissive approach, which in its extreme form essentially regards universities as servants of industry, we can consider the worldwide position with respect to commercial activity in dermatologicals and patches. We can then look at the intellectual challenges that make transdermal research so demanding (a prime role of universities is to seek out and tackle the difficult problems and, particularly, to pose such challenges to their PhD students). In skin research, it is essential that investigators apply fundamental physicochemical principles to an extremely variable and complex biological tissue. The work discussed here provides avenues for further research.

Journal Article↗
PubMed1999

A randomized, double-blind study of a skin patch of a dopaminergic agonist, piribedil, in Parkinson's disease.

This randomized, double-blind trial was designed to evaluate the efficacy of a transdermal system of piribedil on the motor symptoms of Parkinson's disease during 3 weeks of treatment administered to three different groups: placebo, one piribedil patch (1 PP), and two (2 PP) piribedil patches. Twenty-seven patients with idiopathic Parkinson's disease, treated with L-dopa but not sufficiently controlled, were included in this trial. The test treatment did not demonstrate any clinical efficacy on either the main end point (Unified Parkinson's Disease Rating Scale motor score) or the secondary end points (rigidity, bradykinesia, postural, and resting tremor scores). The main adverse events were nausea (11%), vomiting (7.4%), and malaise (7.4%) mainly observed in the placebo group (four of seven patients). The local acceptability of the transdermal system was good. Plasma piribedil concentrations at the end of treatment were 6.74+/-1.10 and 9.31+/-3.33 ng/mL in the 1 PP and 2 PP groups, respectively. These plasma levels could account for the lack of clinical efficacy, because a previous pharmacokinetics-PD study conducted in parkinsonian patients and treated with the intravenous route demonstrated that the critical limits of activity on tremor were between 10 and 30 ng/mL.

Administration, Cutaneous↗
PubMed2000

Physical evaluation of a new patch made of a progestomimetic in a silicone matrix.

The adhesion of a new Transdermal Therapeutic System (TTS) made of silicone and loaded with a progestomimetic drug was characterised. The goal of this study was to use well-known methods or to adapt them to collect representative data. Individually, methods such as surface tension, peel test and rheology are already widely used. Results show that the choice of a substrate for peel tests can be made in the light of surface tension data and that polymers like poly(tetrafluoroethylene) (PTFE) are good alternatives to skin. Peeling characterisations are made a function of thickness of films, drug content in active, conditions of preparation and conditions of use such as pressure. Dynamic rheology is more difficult to link to other methods as it mainly reflects internal phenomena and properties that arise in the bulk, as opposed on its surface. Master curves enable results to be used more easily, but the theories to interpret the data are still not powerful enough to replace peel testing.

Adhesiveness↗
PubMed2002

Transdermal selegiline in major depression: a double-blind, placebo-controlled, parallel-group study in outpatients.

OBJECTIVE: The authors investigated the efficacy and safety of transdermal selegiline in adult outpatients with major depressive disorder. METHOD: Following a 1-week placebo lead-in, 177 adult outpatients with major depressive disorder were randomly assigned to receive transdermal selegiline (20 mg applied once daily by means of a 20-cm(2) patch) (N=89) or placebo (N=88) for 6 weeks. The patients followed a tyramine-restricted diet during the medication trial and for 2 weeks after completion of treatment. Response to medication or placebo was measured by using the 17-item and 28-item versions of the Hamilton Depression Rating Scale, the Montgomery-Asberg Depression Rating Scale, and the Clinical Global Impression (CGI) severity and improvement measures. RESULTS: Greater improvement was observed after 6 weeks in patients treated with transdermal selegiline than in those given placebo according to all measures. A statistically significant difference between drug and placebo was seen in Hamilton depression scale and Montgomery-Asberg Depression Rating Scale scores as early as week 1 of treatment. There were no differences in the adverse event profile of the patients given selegiline and those given placebo with the exception of application-site reactions, which were more common with the selegiline transdermal system. No orthostatic hypotensive or hypertensive reactions were observed. CONCLUSIONS: Transdermal selegiline (20 mg applied once daily by means of a 20-cm(2) patch) administered for 6 weeks was an effective and well-tolerated treatment for adult outpatients with major depression. The typical side effects commonly seen with traditional monoamine oxidase inhibitor antidepressants were not observed.

Administration, Cutaneous↗
PubMed2001

Cardiovascular effects of transdermal nicotine in mildly hypertensive smokers.

Smoking potentiates the enhanced cardiovascular risk of hypertensive patients. Although nicotine replacement therapy is safe when used by healthy individuals to quit smoking, there is no evidence that nicotine replacement therapy is safe in hypertensive smokers. In this crossover, single-blinded, placebo-controlled study, we compared for 4 h the acute effects of transdermal nicotine on the mean arterial pressure (MAP) and heart rate (HR) of mildly hypertensive smokers treated with hydrochlorothiazide with the responses in normotensive smokers and nonsmokers monitored with Finapres and ambulatory blood pressure systems. The plasma concentrations of thromboxane B2 (TXB2, the stable breakdown product of TXA2) were also measured by ELISA to assess whether transdermal nicotine acutely affects TXA2 production. The use of 21-mg nicotine patches increased the MAP and HR in nonsmokers (from 94+/-4 mm Hg and 69+/-3 beats/min to 117+/-7 mm Hg and 83+/-3 beats/min, respectively; P < .05) as well as the MAP in normotensive smokers (from 83+/-4 to 106+/-7 mm Hg; P < .05). However, MAP and HR remained unaltered in hypertensive smokers after transdermal nicotine. Higher basal TXB2 levels were observed in hypertensive smokers compared with normotensive smokers and nonsmokers (2019+/-402 v 670+/-167 and 556+/-68 pg/mL, respectively; P < .05). Transdermal nicotine increased the TXB2 levels only in nonsmokers (P < .05). These data indicate that the use of transdermal nicotine in mildly hypertensive smokers is probably safe. Further studies involving other classes of hypertensive patients are warranted.

Administration, Cutaneous↗
PubMed2002

Potential for use of pulse wave analysis in determining the interaction between sildenafil and glyceryl trinitrate.

BACKGROUND: The early part of the central aortic pressure pulse, with amplitude (PI - Pd), is generated by left ventricular ejection, while the latter part (or augmented pressure), with amplitude (Ps - Pi), is generated by the reflected wave arriving during systole. The effects of arterial vasodilator agents, especially nitrates, on central aortic systolic blood pressure are grossly underestimated by sphygmomanometric measurements of brachial artery pressure. HYPOTHESIS: The objective of this study was to investigate the potential for use of central arterial pulse wave analysis, obtained noninvasively from the radial pulse, in determining the interaction between sildenafil and the nitric oxide donor drug glyceryl trinitrate (GTN). METHODS: Central aortic pressure waveforms were generated from noninvasively measured radial artery pressure wave-forms and subjected to pulse wave analysis to determine the interaction between sildenafil and transdermally applied GTN. RESULTS: Transdermal GTN (2.5, 5.0, and 15 mg per 24-h patches) alone caused no consistent change in sphygmomanometer-determined systolic or diastolic pressures, but there was a consistent, dose-related fall in amplitude of the augmented systolic pressure, (Ps - Pi), of 4.0, 7.0, and 11 mmHg, respectively, with little change in diastolic pressure. The 2.5 mg patch caused a fall of 4.0 mmHg in aortic systolic pressure, while augmentation index (AIx) fell from 20 to 11% and pulse pressure fell 18%. When oral sildenafil (50 mg) was administered after GTN (2.5 mg), aortic systolic pressure fell another 4.0 mmHg. This decrease in systolic pressure caused a fall in AIx to almost 0.0%; pulse pressure fell another 9.0%. CONCLUSION: These modifications in aortic systolic and pulse pressure are due primarily to reduction in wave-reflection amplitude and are not detected by sphygmomanometer-measured brachial artery pressure.

Administration, Cutaneous↗