None listed
Conditions
Brief summary
The absorption of eyedrop medications into the systemic circulation is an uncommon but well known cause of morbidity in glaucoma patients. As a result of Timolol drop application, adverse cardiac and respiratory events in vulnerable individuals are described among other consequences of circulating beta-blockers. Other drops which may be used regularly can also cause adverse effects via systemic absorption. Minimising the amount of drugs that reach the bloodstream is an advice dispensed on every eyedrop drug information and taught worldwide: pressing on the nasolacrimal ducts adjacent to the nose for several minutes (nasolacrimal occlusion). The aim is to stop medications in the tear film draining into the the nose to be absorbed. In papers describing clinical study situations, nasolacrimal occlusion has been shown to decrease blood levels of absorbed beta-blocker drops compared to no action. But in reality it is difficult, may be uncomfortable, and is usually performed poorly for an inadequate amount of time. We suspect that a simpler technique, pressing firmly a dry tissue on the closed eyelid after drop application, will be as effective and much easier to do consistently in the daily life. This study is planned to be a prospective controlled trial. Participation includes applying Timolol 0.5% drops in each eye, followed either by an action, which is thought to reduce systemic uptake or followed by no action. One hour after application a blood sample is taken to detect Timolol plasma levels. Patients are planned to undergo 2 procedures, which are thought to reduce systemic substance uptake and drop application without any following action. Between each procedure will be an interval of at least 1 week to avoid any remaining effects. Therefore participants form their own control group. Participants with risk factors for adverse effects are excluded. The aim is to show the effectiveness of a new procedure in reducing systemic uptake after eye drop application
Interventions
Participation of subjects includes applying Timolol 0.5% eye drops, one drop in each eye (one drop consists of 33 - 64 microliter), immediately followed either by an action, which is thought to reduce systemic uptake or followed by no action at all. The first action (arm 1) is the tissue press method (after applying 1 drop of Timolol 0.5% in each eye, a clean facial tissue is balled-up. It is firmly pressed on one eye, then on the other eye, simultaneously wiping excess medication, which takes a
Participation of subjects includes applying Timolol 0.5% eye drops, one drop in each eye (one drop consists of 33 - 64 microliter), immediately followed either by an action, which is thought to reduce systemic uptake or followed by no action at all. The first action (arm 1) is the tissue press method (after applying 1 drop of Timolol 0.5% in each eye, a clean facial tissue is balled-up. It is firmly pressed on one eye, then on the other eye, simultaneously wiping excess medication, which takes around 2-3 seconds to perform), the second action (arm 2) is nasolacrimal occlusion (after applying 1 drop of Timolol 0.5% in each eye one finger per eye is pressed on the area nasally to the medial canthus for 5 minutes), and no action (arm 3; Timolol 0.5% is applied in each eye. No additional action must be performed then) represents the control. One hour after application a blood sample is taken to detect Timolol plasma levels. Patients are planned to undergo both, two different procedures, which are thought to reduce systemic substance uptake and drop application without any following action. The washout period between each treatment is at least 7 days. Administration of the eye drops is conducted by a member of the staff and the following action is supervised by the the same person to ensure that administration and action are both performed correctly.
Sponsors
Luzia Mueller
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Prevention
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Participants must be 18 years old or more and be able to understand the purpose of this study and perform the interventions following Timolol application. Otherwise, all people, not fulfilling any of the exclusion criteria may be included. Informed consent has to be obtained.
Exclusion criteria
- Health conditions that increase the probability of side effects of Timolol - Hypersensitivity to Timolol or one of the additives - Systemic Beta blocker intake - Inability to understand and perform the instructions - Pregnancy or ongoing breast feeding
Outcome results
None listed