Crampbark (Viburnum opulus) In Russia, the berries are used fresh, or dried for high blood pressure and heart problems. It is also used for coughs, colds, lungs, kidneys, excessive bleeding and stomach ulcers. Externally, a decoction of flowers has been used for skin conditions and eczema. As its name implies, it is known by American practitioners to relieve involuntary muscle cramps and spasms.