Digitalis Source: foxglove (Digitalis purpurea L.; Scrophulariaceae) Used to treat congestive heart failure (‘dropsy’) since 1700s One of the most commonly-prescribed drugs. Blocks Na +, K + -dependent ATPase ( = the sodium ‘pump’) In heart Ca ++ loading in myocytes stronger contractions, more effective pumping of blood In neural tissue altered electrical activity
Digitalis Used to treat delerium tremens and ‘mania’ in 1800s Mania = manic phase of bipolar disorder A so-called narrow safety margin drug Therapeutic range: 0.8 – 2.0 ng/ml > 2.0 ng/ml toxic signs/symptoms > 2.8 ng/ml cardiotoxicity, cardiac arrest
Signs & symptoms of digitalis toxicity Palpitations, irregular pulse, cardiac arrhythmia & arrest Confusion, delerium & agitation, impaired consciousness Photopsis bright spots or flashes of light in visual field Distortion of color vision Yellows and greens accentuated; reds diminished Halos, often green, around light sources Loss of visual acuity
Vincent van Gogh, 1853 –1890 (pixel_RGB.m does the pixel analysis)
Early 1887
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Early 1887
Late August, 1889
June, 1890
Digitalis purpurea