I've been looking around about this, because I have never seen an elderly person on lithium in the first place. Renal clearance issues typically preclude that drug.
I ran Timolol eye drops and timolol tablets thru a drug checker:
Quote:
Search
Check Interactions
No interactions were found for the drugs you selected.
You searched for interactions between the following drugs:
* Lithium Carbonate Capsules
* Timolol Tablets
Add or Delete Drugs
Start Over with a New List of Drugs
(Note: Not all drug interactions are known or reported in the literature, and new drug interactions are continually being reported. This information is provided only for your education and for you to discuss with your personal healthcare provider. )
|
The eye drops contribute much less drug to the body than tablets would and therefore have no interaction listed either:
Quote:
Search
Check Interactions
No interactions were found for the drugs you selected.
You searched for interactions between the following drugs:
* Lithium Carbonate Capsules
* Timolol Hemihydrate Eyedrops
Add or Delete Drugs
Start Over with a New List of Drugs
(Note: Not all drug interactions are known or reported in the literature, and new drug interactions are continually being reported. This information is provided only for your education and for you to discuss with your personal healthcare provider. If eye drops are administered appropriately, the eye drop medication will not be absorbed in large amounts into the bloodstream. Thus, interactions with eye drop medications are typically minimal, but they can occur. You should discuss the use of any eye drop medication and its potential drug interactions with your personal healthcare provider. )
|
However, beta blockers do slow down the heart and therefore, reduce blood pressure. (this is called bradycardia)
Quote:
|
The use of the beta blocker, propranolol (Inderal), with lithium can lead to a slow heart rate and dizziness. Other beta blockers, [for example, metoprolol (Lopressor), atenolol (Tenormin)] also may interact with lithium and be associated with a slow heart rate.
|
from
http://www.medicinenet.com/lithium/page2.htm
I did find a potential explanation for the other drug listed for this patient:
Quote:
Naunyn Schmiedebergs Arch Pharmacol. 2001 Mar;363(3):281-7.Click here to read Links
Effects of icatibant on the ramipril-induced decreased in renal lithium clearance in the rat.
Bagaté K, Grima M, De Jong W, Imbs JL, Barthelmebs M.
Institut de Pharmacologie, Faculté de Médecine, Université Louis Pasteur, Strasbourg, France.
The interaction between an inhibitor of angiotensin I converting enzyme (ramipril) and renal lithium handling was analysed in conscious, normotensive Wistar rats in the absence or the presence of a specific bradykinin B2 receptor antagonist, icatibant. The rats were treated for 5 days with ramipril (1 mg/kg/day p.o.) or its vehicle, alone or together with icatibant (0.1 mg/kg/day, s.c. infusion). Lithium chloride (8.3 mg/kg i.p.) was given as a single dose on day 5. Systolic blood pressure and heart rate were measured by tail plethysmography on day 3 (3, 9 and 15 h after ramipril administration) and renal function on day 4 (0-6 and 6-24 h urine sampling) and day 5 (0-6 h urine sampling). In another group of rats, 24 h sodium excretion was assessed during the first 4 days of ramipril treatment. Ramipril decreased renal lithium clearance (90+/-8 vs. 142+/-10 microl/min/100 g, P<0.001, n=24) and increased the fractional lithium reabsorption (74.3+/-1.9 vs. 66.7+/-1.7%, P<0.05) and plasma lithium concentration (0.108+/-0.006 vs. 0.085+/-0.004 mM, P<0.01). Alteration of renal lithium handling by ramipril was associated with a decrease in systolic blood pressure (-15% 3 h after ramipril administration) and sodium excretion (0-6 h after ramipril). The 24-h sodium excretion, however, tended to increase. Icatibant had no effect per se on renal function but attenuated the ramipril-induced decrease in renal lithium clearance (118+/-16 vs. 90+/-8 microl/min/100 g, n=12 and 24 respectively, P<0.05 one-tailed test) and systolic blood pressure. These results suggest that endogenous bradykinin contributes to the ramipril-associated alteration in renal lithium handling. Bradykinin B2 receptor-mediated vasodilation seems to be involved.
PMID: 11284442 [PubMed - indexed for MEDLINE]
|
Inhibace plus is a combination ACE inhibitor (not available in US) and hydrochlorothiazide.
Not only does the ACE inhibitor family affect lithium, the diuretic hydrochlorothiazide is serious for patients on lithium!
http://books.google.com/books?id=F0n...sult#PPA803,M1
It appears to me that there is more than one serious issue here for this patient. She should NOT be on lithium in the first place if she has hypertension, and/or reduced renal clearance.
The timolol eye drops are a much smaller if any contribution than the Inhibace Plus, from what I can see in the literature!
Thanks for the post, it is a very interesting interaction!
__________________
All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
************************************
.
Weezie looking at petunias 8.25.2017
****************************
These forums are for mutual support and information sharing only. The forums are not a substitute for medical advice, diagnosis or treatment provided by a qualified health care provider. Always consult your doctor before trying anything you read here.